Lean Manufacturing: Fundamentals, Tools, Approaches, and Industry 4.0 Integration 9781003190332

Table of contents :
Cover
Half Title
Title Page
Copyright Page
Dedication
Table of Contents
Preface
Acknowledgments
Author Biography
1 Introduction
1.1 Manufacturing Systems Transition
1.2 Origin of Lean Manufacturing
1.3 Definition and Concepts of Lean Manufacturing
1.4 Comparison of Mass and Lean Manufacturing
1.5 Summary
2 Lean Principles and Waste Categories
2.1 Lean Principles
2.2 Muda, Muri, and Mura
2.3 Waste and Waste Categories
2.4 Waste Analysis
2.5 Kaizen
2.6 Summary
3 Elements of Lean Manufacturing
3.1 Overview on Elements
3.2 Discussion on Elements (Value
Stream and Value Flow)
3.3 Activity Categorization in Value Stream
3.4 Push and Pull Production
3.5 Stability, Standardized Work, and SOPs for Lean System
3.6 Visual Management and Single-Piece Flow Concepts
3.7 Summary
4 Basic Lean Tools (5S and TPM)
4.1 5S Lean Tool
4.2 5S Implementation
4.3 Total Productive Maintenance – Overview and Pillars
4.4 OEE Analysis
4.5 TPM Implementation
4.6 Summary
5 Basic Lean Tools (VSM and Workcell)
5.1 Overview on Process Mapping and Value Stream Mapping (VSM)
5.2 VSM Terminologies and Data Types (Observation/Measurement, Computation Data)
5.3 Construction Steps of Value Stream Maps
5.4 VSM Illustration and Case Study
5.5 Variants of VSM (Advanced Models of VSM)
5.6 Workcell
5.7 Case on Lean Tools Selection
5.8 Summary
6 Supporting Lean Tools and Concepts
6.1 Scope of Supporting Tools
6.2 Description of Core Supporting Tools (Poka Yoke, Kanban, Autonomation, Visual Communication, and SMED)
6.3 Optimized Production Technology, Leveled Production, and Enterprise Resource Planning
6.4 Summary
7 Project Selection and Training for Lean Implementation
7.1 Importance of Project Selection
7.2 Project Selection for Lean Implementation
7.3 Training and Implementation for Lean
7.4 Lean Implementation Levels
7.5 Summary
8 Lean Performance Measurement
8.1 Lean Performance Measures
8.2 Assessment Approaches
8.3 Case Study on Leanness Assessment
8.4 Summary
9 Lean Integration with Other Strategies
9.1 Lean Six Sigma
9.2 Lean and Agile Manufacturing
9.3 Lean Sustainability
9.4 Summary
10 Lean Integration with Industry 4.0
10.1 Need and Scope of Integration
10.2 Insights on Lean and Industry 4.0
Integration
10.3 Analysis of Workforce Attributes for Lean and Industry 4.0
10.4 Summary
11 Research Issues in Lean Manufacturing
11.1 Application Domains in Lean Manufacturing
11.2 Research Avenues in Lean Manufacturing
11.3 Summary
Index

Citation preview

Lean Manufacturing Lean Manufacturing concepts are being applied to a variety of industries. These concepts ensure streamlined processes through a systematic analysis of wastes and elimination, while enhancing value. This book offers fundamentals, theoretical concepts, case studies, and examples, along with insights for lean integration in Industry 4.0. The book offers a comprehensive coverage of topics in Lean Manufacturing which includes lean elements and tools, performance measures, project selection, integration, along with other related strategies. It ensures a balance between theory and practice of Lean Manufacturing by including the implementation aspects of lean tools. The book will explore insights for Industry 4.0 related to lean concepts and provide details on how they relate. Illustrations and examples depicting OEE (Overall Equipment Effectiveness) analysis and value stream map analysis are included. The book also provides case studies on Lean Manufacturing covering value stream mapping, project selection, and performance measurement. Lean Manufacturing: Fundamentals, Tools, Approaches, and Industry 4.0 Integration can be used as a reference for academic researchers and industry practitioners. Undergraduate and postgraduate students can use it for a course on Lean Manufacturing. Doctoral students can also refer to it for advanced concepts, and industry practitioners can use it for practical insights.

Lean Manufacturing

Fundamentals, Tools, Approaches, and Industry 4.0 Integration

S. Vinodh

MATLAB® is a trademark of The MathWorks, Inc. and is used with permission. The MathWorks does not warrant the accuracy of the text or exercises in this book. This book’s use or discussion of MATLAB® software or related products does not constitute endorsement or sponsorship by The MathWorks of a particular pedagogical approach or particular use of the MATLAB® software. First edition published 2023 by CRC Press 6000 Broken Sound Parkway NW, Suite 300, Boca Raton, FL ­33487-2742 and by CRC Press 4 Park Square, Milton Park, Abingdon, Oxon, OX14 4RN CRC Press is an imprint of Taylor & Francis Group, LLC © 2023 Taylor & Francis Group, LLC Reasonable efforts have been made to publish reliable data and information, but the author and publisher cannot assume responsibility for the validity of all materials or the consequences of their use. The authors and publishers have attempted to trace the copyright holders of all material reproduced in this publication and apologize to copyright holders if permission to publish in this form has not been obtained. If any copyright material has not been acknowledged please write and let us know so we may rectify in any future reprint. Except as permitted under U.S. Copyright Law, no part of this book may be reprinted, reproduced, transmitted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying, microfilming, and recording, or in any information storage or retrieval system, without written permission from the publishers. For permission to photocopy or use material electronically from this work, access www. copyright.com or contact the Copyright Clearance Center, Inc. (­CCC), 222 Rosewood Drive, Danvers, MA 01923, 9 ­ 78-­750-8400. For works that are not available on CCC please contact [email protected] Trademark notice: Product or corporate names may be trademarks or registered trademarks and are used only for identification and explanation without intent to infringe. ISBN: ­978-­1- ­032- ­0 4045-5 (­hbk) ISBN: ­978-­1-­032-­0 4046-2 (­pbk) ISBN: ­978-­1-­0 03-­19033-2 (­ebk) DOI: 10.1201/­9781003190332 Typeset in Times by codeMantra

This book is dedicated to my Aunt, Professors, Teachers, Parents, Wife, Son, Students, Friends, and Well-wishers.

Contents Preface Acknowledgments Author Biography 1 Introduction 1.1 Manufacturing Systems Transition 1.2 Origin of Lean Manufacturing 1.3 Definition and Concepts of Lean Manufacturing 1.4 Comparison of Mass and Lean Manufacturing 1.5 Summary

xi xv xvii 1 1 2 2 4 5

2 Lean Principles and Waste Categories 2.1 Lean Principles 2.2 Muda, Muri, and Mura 2.3 Waste and Waste Categories 2.4 Waste Analysis 2.5 Kaizen 2.6 Summary

7 7 8 8 10 10 11

3 Elements of Lean Manufacturing 3.1 Overview on Elements 3.2 Discussion on Elements ( Value Stream and Value Flow) 3.3 Activity Categorization in Value Stream 3.4 Push and Pull Production 3.5 Stability, Standardized Work, and SOPs for Lean System 3.6 Visual Management and Single-Piece Flow Concepts 3.7 Summary

13 13 13 14 15 16 16 17

4 Basic Lean Tools (5S and TPM) 4.1 5S Lean Tool 4.2 5S Implementation 4.3 Total Productive Maintenance – Overview and Pillars 4.4 OEE Analysis 4.5 TPM Implementation 4.6 Summary

19 19 22 24 27 28 30 vii

viii

Contents

5 Basic Lean Tools ( VSM and Workcell) 5.1 Overview on Process Mapping and Value Stream Mapping (VSM) 5.2 VSM Terminologies and Data Types (Observation/ Measurement, Computation Data) 5.3 Construction Steps of Value Stream Maps 5.4 VSM Illustration and Case Study 5.5 Variants of VSM (Advanced Models of VSM) 5.6 Workcell 5.7 Case on Lean Tools Selection 5.8 Summary

33 33 36 37 37 39 42 43 45

6 Supporting Lean Tools and Concepts 6.1 Scope of Supporting Tools 6.2 Description of Core Supporting Tools (Poka Yoke, Kanban, Autonomation, Visual Communication, and SMED) 6.3 Optimized Production Technology, Leveled Production, and Enterprise Resource Planning 6.4 Summary

51 51

54 56

7 Project Selection and Training for Lean Implementation 7.1 Importance of Project Selection 7.2 Project Selection for Lean Implementation 7.3 Training and Implementation for Lean 7.4 Lean Implementation Levels 7.5 Summary

59 59 59 67 68 68

8 Lean Performance Measurement 8.1 Lean Performance Measures 8.2 Assessment Approaches 8.3 Case Study on Leanness Assessment 8.4 Summary

71 71 73 75 89

9 Lean Integration with Other Strategies 9.1 Lean Six Sigma 9.2 Lean and Agile Manufacturing 9.3 Lean Sustainability 9.4 Summary

91 91 92 93 94

51

Contents 10 Lean Integration with Industry 4.0 10.1 Need and Scope of Integration 10.2 Insights on Lean and Industry 4.0 Integration 10.3 Analysis of Workforce Attributes for Lean and Industry 4.0 10.4 Summary

ix 95 95 96 97 98

11 Research Issues in Lean Manufacturing 11.1 Application Domains in Lean Manufacturing 11.2 Research Avenues in Lean Manufacturing 11.3 Summary

105 105 105 108

Index

111

Preface The book aims at addressing theoretical concepts of Lean Manufacturing with a comprehensive coverage of curriculum and insights for industry practitioners. It includes waste analysis, elements, lean tools (­basic and supporting), lean integration with other strategies, lean performance measurement, and insights for lean integration with Industry 4.0. Perceptions for lean integration with Industry 4.0 are highlighted. A book on Lean Manufacturing is based on the authors’ academic experience of teaching the course for undergraduate and postgraduate students as well on research expertise. Efforts have been taken to meticulously discuss fundamental terms and concepts of Lean Manufacturing, which serve as reference for students, scholars, and faculty from academics and practicing engineers. Lean Manufacturing concepts are being applied in wide industrial establishments due to their significance in terms of ensuring streamlined processes through systematic analysis of wastes and elimination, enhancing value from the customer’s perspective, and improving process flexibility. The salient features of the book include a detailed presentation of tools/­ techniques of Lean Manufacturing (­5S, Total Productive Maintenance (­TPM), Value Stream Mapping (­VSM)); metrics associated with lean performance; case studies on value stream mapping, project selection, leanness assessment; examples of lean concepts (­OEE, takt time analysis); research insights on Lean Manufacturing with Industry 4.0. Salient topics include: • Comprehensive coverage of topics in Lean Manufacturing (­elements, tools, performance measures, project selection, integration with other strategies) • Reference for doctoral research students (­ advancements and research issues in Lean Manufacturing) • Inclusion of practical perspectives (­implementation aspects of lean tools) • Insights for Industry 4.0 (­lean concepts for Industry 4.0 and their relevance) • Illustrations and examples (­ OEE analysis, value stream map analysis) xi

xii Preface • Case studies on Lean Manufacturing (value stream mapping, project selection, and performance measurement) • Highlights on practical implications (training and implementation for lean, lean integration with other strategies) • Ensuring balance between theory and practice of Lean Manufacturing (theoretical concepts and case studies with practical relevance) The book provides a description of concepts, supporting illustrations, examples. This book aims at focusing on fundamentals of Lean Manufacturing and its perceptions for practitioners. Case studies on Lean Manufacturing are presented with insights for Industry 4.0. ­

­

Preface xiii ­

Acknowledgments The motivation for the development of this book originates from the research work and publications done by the author for the past 14 years. As the author of this book, I sincerely thank Almighty God for providing me with the energy and strength to complete the writing of the book. I sincerely thank the Director and Administration of our institute and my department for providing the necessary infrastructure and support for book writing. I thank my professors, friends, and well-wishers for their motivation. My special thanks to my beloved Professor Dr S R Devadasan and his mother Mrs Irene N Devadason for their motivation, blessings, and support during book writing. I thank our beloved former Director Professor M Chidambaram for his continued motivation toward book writing. I wholeheartedly thank my scholar Vishal for his continued support during certain stages of book writing. I thank my aunt, father, mother, wife, son, sister, nephew, and other family members for their care and moral support rendered during book writing. I thank all my research group members (past and present students) for their support in various research studies that got published in international journals, which formed the foundation for this book writing. Finally, I would like to thank my publisher CRC Press (Taylor and Francis Group) and the editorial team for their help and support during various stages of book publication.

xv

Author Biography Dr. S. Vinodh is an Associate Professor in the Department of Production Engineering, National Institute of Technology, Tiruchirappalli, Tamil Nadu, India. He completed his Ph.D. degree under All India Council for Technical Education (AICTE) National Doctoral Fellowship scheme from PSG College of Technology, Coimbatore, India. He completed his master’s degree in Production Engineering from PSG College of Technology, Coimbatore, India, and bachelor’s degree in Mechanical Engineering from Government College of Technology, Coimbatore, India. He was a Gold Medalist in his undergraduate study. He has published over 175 papers in international journals. He has research experience in Lean Manufacturing for about 14 years. He received the highly commended Paper Award from Emerald Publishers for the year 2016. He is the recipient of the Institution of Engineers Young Engineer Award for the year 2013 in the Production Engineering Division. He is the recipient of the Innovative Student Project Award 2010 based on his Ph.D. thesis from the Indian National Academy of Engineering (INAE), New Delhi, India. He executed research projects and guided Ph.D. scholars in Lean Manufacturing. His research interests include Sustainable Manufacturing, Lean Manufacturing, Agile Manufacturing, Rapid Manufacturing, Product Development, and Industry 4.0.

xvii

Introduction

1

1.1 MANUFACTURING SYSTEMS TRANSITION Over the decades, manufacturing systems have been witnessing a transition from a craft system to a mass and then further a lean system. A craft system focuses on product manufacturing based on the workforce skillset. A few product variants based on predicted demand as well as customers’ preferences are manufactured. Craft products were limited to certain geographical regions. Mass production is supported with interchangeability and moving assembly lines. Mass manufacturing is characterized by high-volume production based on dedicated assembly lines or product lines. Mass manufacturing is based on economies of scale, which state that the unit cost of a product comes down as a result of high volume production. Mass production enables low-cost manufacturing of large volumes through dedicated manufacturing lines. Product variants are limited. Mass customization facilitates a response to customer demands with high product variants and options (Hu et al., 2011). Lean manufacturing is characterized by streamlined processes by means of waste elimination. It ensures flexibility of processes from the viewpoint of dealing with few product variants. Lean is based on a pull system where product manufacturing is based on customer demand. Lean and agile systems focus on greater control of the supply chain by developing long-term collaborative relationships with suppliers (Barlow, 1999). An agile system focuses on developing product variants in line with customers’ varied preferences. An agile system includes lean and flexibility components. A sustainable system includes the development of environmentally friendly products/processes with Triple Bottom Line (TBL) benefits. A smart system focuses on developing a smart factory system based on a Cyber-Physical System (CPS) to consider human-equipment interactions for ultimately developing a smart factory. The transition of manufacturing systems is depicted in Figure 1.1.

DOI: 10.1201/9781003190332-1

1

2  Lean Manufacturing Mass System

Agile System

Smart System

Craft System

Lean System

Sustainable System

­FIGURE 1.1  Transition of Manufacturing rSystems

1.2 ORIGIN OF LEAN MANUFACTURING Lean manufacturing has its origins in the Toyota Production System (TPS) based on JIT (Just In Time) principles, which implies that the raw material has to be procured just in time, the product manufactured just in time, and the product delivered just in time based on customer demand. A JIT system enables inventory handling effectively and inventory reduction is facilitated. In line with TPS adoption from Japanese industries, the term “Lean” has been brought into practice based on the book written by James Womack – The Machine that Changed the World. From then onward, the term lean has been brought into practice. The term “Lean” indicates lesser of everything, i.e. space, inventory, people, or time. Lean is concerned with setting the process speed regulated by customer demand. Lean manufacturing originated in Japan and TPS applied lean practice first. Lean manufacturing was in contrast to conventional manufacturing with the focus on inventory reduction, as lean visualizes inventory as waste. Lean manufacturing has its focus on product value visualization from the customer viewpoint (Gupta and Jain, 2014). The birth of lean was with Japanese TPS in the 1940s, which was based on the idea of facilitating continuous flow ( Melton, 2005). Lean production originated from TPS with the concept of recognizing and eliminating waste in line with the lean definition. Lean production is based on the Kaizen approach (continuous improvement).

1.3 DEFINITION AND CONCEPTS OF LEAN MANUFACTURING This section presents definitions and concepts of lean manufacturing.

1 • Introduction  3

1.3.1 Definitions of Lean Manufacturing Lean is defined as a process with five steps: first customer value, second value stream, third value flow, fourth pull system, and fifth Continuous Improvement (CI). Standardization of work processes and procedures is essential with sustenance of improvements (Gupta and Jain, 2014). Lean thinking is associated with the following principles: value identification, waste elimination, and flow generation (Melton, 2005). With reference to the widely cited definitions of lean manufacturing in literature (Shah and Ward (2003); Holweg (2007)), it can be inferred that lean manufacturing is defined as the capability of a manufacturing system to ensure streamlined processes, waste elimination, and value addition. Lean ensures production in line with customer demand (pull system). A lean system includes a set of elements, tools/techniques, governing rules for enhancing the competitive performance of organizations.

1.3.2 Concepts of Lean Manufacturing Lean manufacturing implies speedy, smooth, and economical manufacture. The term speed implies that manufacturing processes have to be done at a pace based on customer demand. The term smooth implies that the fluctuations (variations) need to be controlled. The term economical manufacture implies that a lean system has to be done with the focus on cost reduction based on economies of scale. Lean manufacturing concepts can be applied to any kind of processes irrespective of the type of product being manufactured. Lean manufacturing is based on the Kaizen philosophy of continuously improving the process, standardization of work procedures, and sustaining the improvements attained. Lean manufacturing aims at elimination of waste, streamlining the processes, and enhancing value addition. The term “lean” implies lesser of everything, i.e. space, inventory, people, and time. Lean manufacturing regulates speed of manufacturing in line with customer demand, smooth manufacturing in terms of fewer fluctuations, and economical manufacture in terms of reduced cost with waste elimination. Lean manufacturing is based on the Kaizen approach and aims at CI of processes irrespective of products being manufactured. Lean manufacturing concepts can be applied to any kind of industry (product manufacturing, process based, SMEs.). A lean system focuses on the customer in terms of enhanced value addition from the customer’s perspective. A lean system is flexible and adaptable to processes. Lean concepts synchronize processes and

4  Lean Manufacturing enable pull production. A lean system aims at worker-driven CI in terms of having focus on promoting innovative culture in the organization.

1.4 COMPARISON OF MASS AND LEAN MANUFACTURING Mass production is associated with inventory buffers whereas lean production has minimum inventory in specific lesser Work In Process (WIP). A mass system aims at Just In Case deliveries whereas a lean system enables JIT deliveries. Mass production aims at Acceptable Quality Level (AQL) whereas a lean system aims at perfect first time quality. Mass production aims at maximizing efficiency whereas a lean system aims at process flexibility and CI. Mass production is aimed at repetitive manufacture of similar products through assembly lines. Lean production is incorporated with process flexibility in terms of handling few product variants through quick change over concepts.

1.4.1 On Time Delivery A mass system permits early/ late delivery; a lean system is based on JIT delivery.

1.4.2 Good Quality A mass system ensures quality through inspection whereas a lean system ensures quality by in-process gauging.

1.4.3 Low Price A mass system facilitates cost reduction through economies of scale, whereas a lean system does so by waste elimination.

1.4.4 Objectives A mass system aims at cost reduction and efficiency improvement, whereas a lean system focuses on waste elimination and value addition.

1 • Introduction

5

1.4.5 Improvement A mass system aims at expert-driven improvement, whereas a lean system aims at worker-driven improvement.

1.4.6 Focus A mass system focuses on product, whereas a lean system focuses on the customer.

1.4.7 Production Method A mass system deals with a high volume of standardized products, whereas a lean system makes products in line with customer order.

1.4.8 Skill Mass production requires a narrowly skilled workforce, whereas a lean system requires teams of multi-skilled workers. Lean manufacturing combines features of both mass and craft production with reduction of cost per product and improvement in quality (Pavnaskar et al., 2003). A lean system focuses on cost reduction with quality improvement with minimal resources (Duguay et al., 1997).

1.5 SUMMARY This chapter presented the manufacturing system transition and discussed the characteristics of craft, mass, lean, agile, sustainable, and smart systems. The origin, definition, and concepts of lean manufacturing were discussed. A comparison of mass and lean manufacturing was presented from several perspectives.

REFERENCES Barlow, J. (1999), ‘From craft production to mass customisation. Innovation requirements for the UK Housebuilding industry’, Housing Studies, 14:1, 23–42.

6

Lean Manufacturing

Duguay, C.R., Landry, S., and Pasin, F. (1997), ‘From mass production to flexible/agile production’, International Journal of Operations  & Production Management, 17:12, 1183–1195. Gupta, S., and Jain, S.K. (2014), ‘A literature review of lean manufacturing’, International Journal of Management Science and Engineering Management, 8:4, 241–249, DOI: 10.1080/17509653.2013.825074. Holweg, M. (2007), ‘The genealogy of lean production’, Journal of Operations Management, 25:2, 2, 420–437. Hu, S.J., Ko, J., Weyand, L., ElMaraghy, H.A., Lien, T.K., Koren, Y., Bley, H., Chryssolouris, G., Nasr, N., and Shpitalni, M. (2011), ‘Assembly system design and operations for product variety’, CIRP Annals – Manufacturing Technology, 60, 715–733. Melton, T. (2005), ‘The benefits of lean manufacturing – what lean thinking has to offer the process industries’, Chemical Engineering Research and Design, 83:6, 662–673. Pavnaskar, S.J., Gershenson, J.K., and Jambekar, A.B. (2003), ‘Classification scheme for lean manufacturing tools’, International Journal of Production Research, 41:13, 3075–3090, DOI: 10.1080/0020754021000049817 Shah, R., and Ward, P.T. (2003), ‘Lean manufacturing: context, practice bundles, and performance’, Journal of Operations Management, 21:2, 129–149.

Lean Principles and Waste Categories

2

2.1 LEAN PRINCIPLES Lean principles are referred from literature studies (Azadeh et al., 2017) and practical perspectives and are discussed below: • Customer perspective – Understanding customer requirements exactly. Lean system focuses on compliance with customer requirements effectively. • Waste reduction – Identification of entities that do not add value from a customer perspective. As waste does not add value from the customer’s perspective, wastes need to be reduced and eliminated. • Product value from the customer viewpoint – Lean aims at fulfilling product value from the customer’s viewpoint and not from the manufacturer’s viewpoint. • Pull system – Producing products based on customer demand. Product manufacture is in line with customer demand. • Non-value-adding activities elimination – Lean aims at minimization and elimination of wastes. • Doing right the first time – Lean aims at executing activities right the first time without any mistakes. • Perfect first-time quality – Lean concepts are based on in process gauging with quality compliance perfectly. • Delivery of material right time – Suppliers have to supply raw material at the right time to initiate the value stream.

DOI: 10.1201/9781003190332-2

7

8  Lean Manufacturing • Streamlining of inventory – Inventory has to be reduced and streamlined to ensure a smooth flow of value stream. • Synchronization of processes – Processes have to be synchronized by reducing inventory and setup time. • Utilization of creative skills of the workforce – Creative and innovative skillset of the workforce has to be utilized to enable process innovation.

2.2 MUDA, MURI, AND MURA The terms muda, mura, and muri are discussed as follows (Pieńkowski, 2014). Muda implies waste or uselessness. It implies waste-generated tasks. As per lean theory, seven types of muda are reported. These include unnecessary transportation, unnecessary inventory, waiting, unwanted motion, overproduction, inappropriate processing, and defects or nonconformities. Muda leads to non-value-added tasks and have to be eliminated. Muri implies overburden. It occurs due to the waste of overloading machinery, equipment, or people beyond capacity. Muri occurs due to a disorganized workstation and the lack of standardized work. Muri implies waste that happens due to overburdening facilities beyond the capacity/demand. Muri can be remedied using organized workstations and standardized work. Mura implies variation or unevenness. It implies waste or unevenness in production volume. Forms of mura include variation in production scheduling or uneven production workload. Mura indicates uneven fluctuations. Mura can be controlled by minimizing scheduling fluctuations or production workload fluctuations.

2.3 WASTE AND WASTE CATEGORIES Waste is an entity that consumes resources but does not add value from a customer’s perspective. Waste types are depicted in Figure 2.1. Seven fundamental waste categories are discussed as follows: Overproduction – Producing more than what the customer has asked for Overprocessing – It includes unnecessary or inappropriate processing

2  •  Lean Principles and Waste Categories  9

T

I

M

1

2

3 Seven Waste

W

4

T – Transport I – Inventory M – Motion

5

O

W – Waiting O – Overproduction O – Overprocessing

6

7

O

D - Defects

D

­FIGURE 2.1  Waste Types

­

Apart from seven fundamental wastes, the following two wastes are being considered in lean theory. Underutilization of workforce creativity or the untapped creativity of workforce – As lean relies on process innovation, not utilizing workforce creativity becomes waste Environmental waste – It refers to wastes in terms of emissions or environmental impacts

10  Lean Manufacturing ­TABLE 2.1  Waste Analysis WASTE Multiple handling Excess safety stock Unsold items Inappropriate layout Excess queue Late delivery Producing more than required Inappropriate processing steps Scrap Rework

WASTE CATEGORY

PROPORTION (%)

Transportation Inventory

10 20

Motion Waiting

10 20

Overproduction Overprocessing Defects

10 10 20

Total

100

2.4 WASTE ANALYSIS Following wastes are being analyzed and mapped to waste category with the corresponding proportion. Table 2.1 presents waste analysis.

2.5 KAIZEN The term “Kaizen” was derived from the Japanese manufacturing philosophy of creative strategy for business success. Kaizen is a Japanese term which implies Continuous Improvement (CI). Kaizen is aimed at CI of the process which forms the basis for business success. Kaizen is based on process improvement through human effort. In line with the view of Imai, the process-oriented method is referred to as the PDCA (Plan-Do-Check-Act) ­­ ­ ­ cycle of CI. The further cycle is called the standardization cycle SDCA (Standardize-DoCheck-Act) ­ cycle. The two cycles of PDCA and SDCA facilitate CI culture in the organizations. Kaizen also aims at performance improvement in terms of Quality, Cost, Delivery (QCD) dimensions (Smadi, 2009). Some of the tools of Kaizen include:

2 • Lean Principles and Waste Categories

11

• 5 Why technique – To identify the root cause of problem • 5S – To promote an organized workplace • Waste elimination (Muda) – Customers do not pay for any activity which does not add value • PDCA cycle – Improvement cycle • Poka yoke – Prevents the occurrence of defects (mistakes) Kaizen enables the organization-wide process of focused and sustained incremental improvement by ensuring employee involvement at every level of the organization. Kaizen enables an organization to attain world class status through long-term drive and commitment toward success and profitability.

2.6 SUMMARY This chapter presented a discussion on various lean principles. Concepts of muda, muri, and mura were briefed. Waste types were presented. Waste analysis was presented with a discussion on kaizen concepts.

REFERENCES Azadeh, A., Yazdanparast, R., Zadeh, S.A., and Zadeh, A.E. (2017), ‘Performance optimization of integrated resilience engineering and lean production principles’, Expert Systems with Applications, 84, 155–170, DOI: 10.1080/17509653.2013.825074 Pieńkowski, M. (2014), ‘Waste measurement techniques for lean companies’, International Journal of Lean Thinking, 5:1, 9–24. Sami Al Smadi, (2009), ‘Kaizen strategy and the drive for competitiveness: challenges and opportunities’, Competitiveness Review: An International Business Journal, 19:3, 203–211, DOI: 10.1108/10595420910962070

Elements of Lean Manufacturing

3

3.1 OVERVIEW ON ELEMENTS The elements of a lean system have to be clearly understood before implementation. They are depicted in Figure  3.1. The five elements include customer value, value stream, value flow, customer pull, and perfection by Continuous Improvement (CI) (Gopalakrishnan, 2010). The customer expects value for money being paid in a lean organization. Product value is ensured if it fulfills the customer’s known and perceived requirements. Product value from the customer’s viewpoint is essential. Though the manufacturer may claim that product value is being fulfilled, product value fulfillment from the customer’s perspective is essential. Elements are based on chronology. After recognizing customer value, a value stream is set, and value flow occurs followed by customer pull and CI with sustenance.

3.2 DISCUSSION ON ELEMENTS (VALUE STREAM AND VALUE FLOW) Value stream denotes the sequence of activities in product manufacture from beginning to end where cost is incurred and value is created. Value creation is DOI: 10.1201/9781003190332-3

13

14  Lean Manufacturing Perfection by C.I

Customer Value Pull System Value Flow

Value Stream

­FIGURE 3.1 

Elements of Lean Manufacturing

ensured in a value stream. In contrast, in a process stream, which happens in batch/mass production, cost is incurred but value creation is not ensured. In a value stream, three types of activities are prone to occur:

I. Customer ­Value-Added (CVA) ­ II. Necessary but ­Non-Value-Added ­ (NNVA) ­ III. ­Non-Value-Added ­ (NVA) ­ The objective is to maximize value-added activities. A product manufactured using a value stream based on customer demand is value flow. In contrast, product flow happens in batch/mass production, where product manufacture is done using a process stream based on predicted/forecasted customer demand. The value flow has to be smooth without any bottlenecks. Bottlenecks have to be removed to ensure that the value flow is happening without any hurdles. Bottlenecks include poorly organized layout, non-understanding of customer requirements, production held up through improper tooling, downtime, productivity variation across shifts.

3.3 ACTIVITY CATEGORIZATION IN VALUE STREAM There are three types of activities in a value stream:

3  •  Elements of Lean Manufacturing  15

1



2



3

CVA – These activities are done for fulfilling customer requirements and are essential for ensuring product performance. These activities have to be focused meticulously. The proportion of CVA activities serves as a benchmark for organizations. Examples: Drilling, milling, or grinding process with the focus on value addition. BVA – These activities are forcefully induced in the process because of government regulations and compliance procedures. These activities do not add value but are essential for completion of business processes. Examples: Inspection due to compliance with government regulations and procedures. NVA – These activities do not add value and are sheer waste. Removal of these activities does not affect product performance. Lean concepts aims at elimination of these activities. Example: Seven forms of wastes belong to NVA activities.

3.4 PUSH AND PULL PRODUCTION Push production: Production is based on forecasted demand. Products are produced and pushed to market with the scope for selling. In this production type, more inventory gets accumulated. Products may get obsolete. Work In Process (WIP) will not be limited (Hopp and Spearman, 2004). Product is produced without knowing customer need. Mass production is push based as it caters to market forecast and customer demand. All three forms of inventory (Raw Material Inventory (RMI), WIP, and Finished Goods Inventory (FGI)) get accumulated in a push system. Interruptions happen in a process stream with reference to push production. Pull production: Production is based on customer demand. Products are produced with definite customer need. In this production, inventory is reduced. WIP is also limited (Hopp and Spearman, 2004). A pull system is based on demand from both external and internal customers. Lean production is pull based as it produces purely based on customer demand. As the system works based on customer demand, WIP occurs, which can be streamlined. Pull production aims to streamline inventory so that products can be manufactured and delivered just in time to the customer.

16  Lean Manufacturing

3.5 STABILITY, STANDARDIZED WORK, AND SOPS FOR LEAN SYSTEM Stability refers to making the system stable with minimization of fluctuations. Standardization aims at ensuring consistency wherein process steps and procedures are executed repeatedly. Lean aims at standardized procedures and instructions to ensure consistency (EL-Khalil et al., 2020). Standardization reduces process variations for improving operational efficiency and effectiveness. Standard Operating Procedures (SOPs) and Standard Instructions (SIs) are evolved to control fluctuations in system due to handling by different operations. As variations happen because of operators getting changed as per shift, procedures and instructions need to be standardized. Reasons for unstability need to be found and the system has to be made stable. Unstability may result from various factors such as machinery, tooling, man, and so on. Once the causes for unstability are found and removed, the system is made stable. Standardized work ensures work procedures need to be standardized to ensure consistency. SOPs need to be evolved to ensure that system variations are minimal. The effectiveness of the system can be ensured through stabilization, standardization, and evolving SOPs. In line with SOPs, SIs need to be evolved.

3.6 VISUAL MANAGEMENT AND SINGLE-PIECE FLOW CONCEPTS Visual management is applied as a comprehensive system to facilitate an effective understanding by means of displaying trend charts, work schedules, problem areas. It enables effective and immediate feedback. Also, it includes techniques to enable visual communication, visual control, and visual workplace. Lean emphasizes on visual management to uncover the hidden aspects. Lean brings about transparency in operations. Single-Piece Flow (SPF) enables the manufacture of a product one by one as a single component without any delays/inventory ­ ­pile-up. Visual management reveals bottlenecks and it contributes to operational transparency. Some of the cited functions of visual management include transparency, CI, simplification, and so on (Yik and Chin, 2019). Lean tries to

3 • Elements of Lean Manufacturing

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uncover hidden issues and promote system transparency. Visual management in terms of evolving visual controls and promoting visual communication has to be ensured. Lean concepts are concerned with transforming batch production to SPF. SPF facilitates production of parts one by one and enables synchronized production with inventory reduction. Product movement happens in a regulated manner without bottlenecks/interruptions.

3.7 SUMMARY This chapter presents the discussion on various lean elements. Concepts of value stream and value flow are briefed. Three types of activities in the value stream are discussed. Push and pull production concepts are briefed. Stability, standardized work, and SOPs for a lean system are presented with a discussion on visual management and SPF concepts.

REFERENCES EL-Khalil, R., Leffakis, Z.M., and Hong, P.C. (2020), ‘Impact of improvement tools on standardization and stability goal practices an empirical examination of US automotive firms’, Journal of Manufacturing Technology Management, 31:4, 705–723. Gopalakrishnan, N. (2010), Simplified Lean Manufacture – Elements, Rules, Tools and Implementation, PHI Learning Private Limited. Hopp, W.J., and Spearman, M.L. (2004), ‘To pull or not to pull: what is the question?’ Manufacturing  & Service Operations Management, 6:2, 133–148, DOI: 10.1287/msom.1030.0028 Yik, L.K., and Chin, J.F. (2019), Application of 5S and Visual Management to Improve Shipment Preparation of Finished Goods, IOP Conf. Series: Materials Science and Engineering 530, 012039.

Basic Lean Tools (5S and TPM)

4

A lean system includes four primary or basic tools (5S, Total Productive Maintenance (TPM), Value Stream Mapping (VSM), and workcell). The basic tools are shown in Figure 4.1. Any lean implementation begins with the implementation of basic tools. Among these primary tools, 5S is one of the basic tools to be concentrated for first-level implementation, as 5S initiatives might be prevailing in the organizations prior to lean implementation. Another viewpoint from literature analysis is that VSM can be focused for initial implementation. As a part of VSM implementation, all associated lean tools can be enabled for implementation, thereby enhancing lean performance of the organization.

4.1 5S LEAN TOOL The 5S lean tool is presented in this section. 5S stands for Seiri, Seiton, Seiso, Seiketsu, and Shitsuke meaning sort, set in order, shine, standardize, and sustain, respectively. It facilitates an organized workplace and is used to ensure an efficient and effective work area.

4.1.1 Introduction to 5S 5S facilitates a meticulous approach for efficient results from the perspective of workplace organization. It reduces wastage and contributes toward workplace safety improvement. Also, it provides a disciplined approach for the organization (Randhawa and Ahuja, 2017). ­

DOI: 10.1201/9781003190332-4

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20  Lean Manufacturing

5S

TPM Basic Tools

VSM

­FIGURE 4.1 

Work Cell

Basic Lean Tools

Set in order – It enables orderly positioning of items for ease of convenient usage and easy access to necessary materials at required places along with ease of accessibility. ­ ­

4.1.2 Description of the 5S Lean Tool 4.1.2.1 Seiri (Sort) ­ The first element tries to segregate items in use and not in use. It tries to categorize items adding value and not adding value from the customer’s perspective. In this step, items not in use are identified and positioned category wise,

4  •  Basic Lean Tools (5S and TPM)  21

Seiketsu

Shitsuke

Seiso

Seiton

Seiri

­FIGURE 4.2  Scheme of 5S

then red tags are attached to those items, and the red-tagged items are positioned category wise, Cross-Functional Teams (CFTs) are formed for disposal, and disposal actions are taken.

4.1.2.2 Seiton (Set in Order) It promotes orderliness whereby there is a place for every entity and they have to be in their designated place. Key equipment are identified, their locations are indicated, and shadow boards are developed. A shadow board is depicted in Figure 4.3. In this step, items are arranged in such a way that there is no waste. Shadow boards are developed to facilitate the storage and retrieval of tools.

4.1.2.3 Seiso (Shine) ­ Routine cleaning and inspection is done to analyze work conditions. Check points for performance and visual controls are developed.

22  Lean Manufacturing

­FIGURE 4.3  Shadow Board Sketch

The term clean implies items must be ready for immediate usage. It extends to workplace machinery, tools, documents, moving and safety equipment.

4.1.2.4 Seiketsu (Standardize) ­ In this step, common methods are ensured for consistency. Standard procedures are evolved. The 5S audit is done to monitor 5S performance. A radar chart is used to record the results of the 5S performance.

4.1.2.5 Shistuke (Sustain) ­ It facilitates the development of commitment to make 5S a way of life. The 5S level of attainment is found, routine checks are analyzed, and Continuous Improvement (CI) is planned. In this element, the workforce is trained on good housekeeping discipline, and self-discipline and self-awareness and the procedures are sustained. Communication boards are formed, before and after photos are maintained, visual standards are developed, and a monthly review is done.

4.2 5S IMPLEMENTATION The importance and significance of 5S has to be communicated among all stakeholders by demonstrating management commitment. Workarea

4  •  Basic Lean Tools (5S and TPM)  23 deployment teams have to be formed and must continue focused efforts. Implementation targets have to be set and accordingly the activity plan and schedule derived. The present situation needs to be documented. 5S (Seiri, Seiton, Seiso, Seiketsu and Shitsuke) has to be applied. Improvements have to be documented and new goals have to be derived with action steps to be implemented.

4.2.1 5S Implementation Plan • Commitment from senior management is essential for 5S implementation. An open meeting should be conducted to demonstrate the need for lean implementation. Employee involvement needs to be ensured for lean implementation. • A cross-functional team needs to be formed with members from different divisions to implement 5S. The team needs to include leaders and members involved in 5S implementation. • Training needs to be provided for lean leaders, production supervisors, shop workers, supply chain staff on 5S. The duration may vary from one level of workforce to another. • A pilot area should be selected for 5S implementation, which is critical for 5S implementation in terms of disorganized workplace. Also, the area where more transportation and motion wastes happen should be selected. • 5S (Sort, Set in Order, Shine, Standardize, and Sustain) needs to be done. Vital activities include red tagging and recording disposal actions, shop floor reorganization, tools positioning using shadow boards, developing visual controls, cleaning standards development, evolving Standard Operating Procedures (SOPs), sustenance plans. • 5S auditing is conducted to determine the 5S performance score. A spider chart/radar chart is developed to analyze the results of 5S auditing. Areas requiring improvement are identified based on a 5S audit. • Photograph recording and video recording (“As Is” and “To Be” scenarios) are undertaken to capture present and future scenarios. • Periodical review is conducted to check whether the projects are progressing as per plan. Review results are monitored. • Appropriate rewarding schemes need to be developed to recognize the workforce efforts on 5S implementation schemes which include incentives, newsletters, magazines, highlighting the success stories.

24  Lean Manufacturing

4.2.2 5S Implementation for SME In the context of Small and Medium Enterprise (SME), orientation sessions need to be conducted to highlight the significance of 5S adoption and benefits of implementing 5S. A team of employees has to be formed and trained on 5S implementation. The pilot area has to be selected where productivity issues happen. This is followed by implementation of Seiri, Seiton, Seiso, Seiketsu, and Shitsuke. All activities pertaining to various 5S elements need to be done. • The procedural steps for 5S implementation for a large-scale organization have to be amended for a small-scale organization. • Organization-wide implementation of 5S should be focused. • As 5S can be focused on implementation for a SME, a dedicated team needs not be formed. Available employees should be involved in implementation. • Training with external expertise should also be initiated.

4.3 TOTAL PRODUCTIVE MAINTENANCE – OVERVIEW AND PILLARS The origins of TPM are in Preventive Maintenance (PM). Also, initially Total Quality Management (TQM) concepts were applied for maintenance problems. But they were not found to be fully compatible. Then the specialization of TPM was brought into practice. Concepts of TPM This ensures long-term commitment by organizational employees and there is a recognition of clear, specific, and quantifiable goals and targets. Small improvements must be undertaken on a continuous basis. There should be elimination of wastage and losses with increasing efficiency and productivity and safety improvement. Prime goals of TPM The prime goals of TPM are zero defects, zero accidents, and zero breakdowns (Poduval et al., 2015). The key goal of TPM is to eliminate all manufacturing-related losses to enhance production effectiveness.

4  •  Basic Lean Tools (5S and TPM)  25

4.3.1 TPM Pillars



2. Equipment and process improvement This pillar aims at maximizing efficiency with the elimination of wastes and manufacturing losses. Manufacturing losses are 13 losses (six equipment related, four manpower related, and three material related). Overall Equipment Effectiveness (OEE) indicates efficiency of the machinery/equipment during its planned loading time. It is the product of availability, performance efficiency, and quality yield. OEE = A × PE × Q

(4.1)

The calculated OEE should be 85% as per the world class threshold. Availability can be ensured by reducing downtime, planned maintenance time, setup time. Performance efficiency can be improved by ensuring actual production in line with planned production. Quality can be improved by reducing defects through in-process gauging-based inspection and conformance to quality standards. 3. Planned maintenance This pillar aims at preventive and predictive maintenance for equipment to ensure natural life cycle of individual machine elements. The natural life cycle of machine elements can be ensured by appropriate procedures during the design phase.

26  Lean Manufacturing can be correlated with a practical perspective wherein manufacturers are very much concerned with the initial operating period of machinery/equipment. This observation coincides with the reliability curve wherein the initial stage (introduction failures) and the last stage (worn-out failures) happen. The second stage is the useful lifetime.



6. Office TPM This pillar aims at ensuring implementation in administration and support departments to ensure effective information flow. As administrative departments have to be coordinated with the production division, the information flow regarding maintenance activities needs to be regulated across administrative and support departments.



8. Safety and environmental management This pillar ensures safety and avoids adverse environmental impacts in TPM initiatives. This pillar aims at safer operating conditions of machinery/ equipment. As material losses can be minimized using the second pillar of TPM (equipment and process improvement), both these pillars facilitate optimal resource utilization and environmental impact minimization. Figure 4.4 depicts the TPM pillars (eight pillars). They include autonomous maintenance, equipment and process improvement, planned maintenance, early management of new equipment, process quality management, office TPM, education and training, and environmental management. Although eight pillars need to be focused on as a part of TPM implementation, The relative contribution of the pillars varies from a large-scale organization to a medium- and further small-scale organization.

4  •  Basic Lean Tools (5S and TPM)  27 3. Planned maintenance

4. Early management of new equipment

8. Safety and environment management

7. Education and Training

3

2. Equipment and process improvement

2

TPM

4

1. Autonomous maintenance

1

8

5

PILLARS 7

6

5. Process quality management

6. Office TPM

­FIGURE 4.4  Eight Pillars of TPM

4.4 OEE ANALYSIS 4.4.1 OEE The “availability” element is concerned with total stoppage time resulting from various reasons. It is the ratio of actual operating to planned operating time (Dal et al., 2000). A vital factor is loading time. The loading time denotes the total shift time after deduction for planned downtime. It includes non-availability of labor, planned maintenance, equipment trials, machine cleaning operators’ training, and so on. The second element, i.e. the “performance rate”, is the ratio of actual speed to ideal speed of equipment.

28  Lean Manufacturing The third element, i.e. the “quality rate”, is used to indicate quality performance with consideration of defects. OEE is an indicator of the effectiveness of the machinery/equipment during its planned loading time. OEE calculation for milling machine Shift time = 8 hours = 480 minutes Maintenance time (planned) – 30 minutes Downtime – 30 minutes Setup time (average) – 20 minutes Available time = 480 – 80 = 400 minutes Planned production – 250 units Actual production – 200 units Performance efficiency = 200/250 = 80% Quality – 99% OEE = A × PE × Q = .833 × .80 × .99 OEE = 65.9%

4.4.2 Analysis To increase availability, the planned maintenance time should be reduced; reasons for downtime can be explored and minimized and the average setup time can be reduced by adopting Quick Change Over (QCO). The reasons for deviation in actual production can be identified and reduced and hence performance efficiency can be ensured, thereby improving OEE.

4.5 TPM IMPLEMENTATION Top management announce TPM implementation where they demonstrate commitment and involvement of top management. • Significance of TPM is demonstrated to all stakeholders with intensive training • TPM implementation teams are formed • Targets for TPM implementation are set • Activity plan and scheduling is undertaken • OEE is calculated

4  •  Basic Lean Tools (5S and TPM)  29 • • • •

Critical projects are identified PM is undertaken Scheduled maintenance is undertaken Revised procedure is implemented

TPM aims at improving the firm’s productivity and ensuring quality products through waste minimization and cost reduction. TPM aims at optimizing manufacturing equipment effectiveness.

4.5.1 TPM Implementation Plan • Top management must demonstrate their commitment toward TPM implementation. Involvement of employees must be ensured. Management must present case studies of TPM implementation in other organizations and highlight the benefits of TPM implementation. • The goal statement must indicate the objective of TPM implementation and strategies are the ways to ensure TPM implementation. For example, the goal could be enhancement of OEE, which is facilitated through strategies such as increase in availability, performance efficiency, and quality. Detailed plans are evolved for TPM implementation, highlighting various activities concerned. • Workforce from different divisions must be formed as teams for implementation. Shop workforce needs to be trained on maintenance activities. Training should be done for operational and maintenance activities. A training plan should be evolved and subjected to implementation. • TPM activities need to be initiated. • The pilot area should be selected based on critical maintenance activities. The pilot area where OEE of machineries/equipment are found to be less needs to be identified. • Present maintenance activities need to be analyzed. The map of the present scenario needs to be done and the revised procedure arrived at. Maintenance activities (autonomous) activities need to be done. • Along with PM, scheduled maintenance needs to be done. • This is followed by standardization of processes/procedures for maintenance activities and CI initiatives to be done. • Best performing teams have to be rewarded for their maintenance effectiveness contribution.

30

Lean Manufacturing

4.5.2 Role of Industry 4.0 Technologies in TPM • Internet of Things (IoT) helps in monitoring of OEE with capturing of data parameters for Availability, Performance, and Quality. IoT facilitates remote monitoring of machineries/equipment through the cloud system. IoT helps shop managers to remotely manage shop activities in terms of maintenance data updates through application and the cloud system. In this context, the shop manager can attend to maintenance issues in any of the machine tools across several manufacturing shops. • Industrial IoT ( IIoT) includes enhanced form of IoT with sensors and actuators to enable diversified functions with regard to TPM. • An augmented reality system includes digitalization of history data of machinery/equipment. The digital history card includes complete breakdown data and maintenance actions. • Equipment and Process Improvement pillar enables the safety and environmental management pillar wherein optimal resources utilization and minimization of environmental impact are facilitated.

4.6 SUMMARY This chapter presents the introductory aspects and description of 5S lean tool. The general 5S implementation plan and plan for SME are presented. The fundamentals and eight pillars of TPM are presented. OEE computation and analysis are discussed. The TPM implementation plan and the role of Industry 4.0 technologies enabling TPM have been discussed.

REFERENCES Dal, B., Tugwell, P., and Greatbanks, R. (2000), ‘Overall equipment effectiveness as a measure of operational improvement – a practical analysis’, International Journal of Operations & Production Management, 20:12, 1488–1502.

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Poduval, P.S., Pramod, V.R., and Jagathy Raj, V.P. (2015), ‘Interpretive Structural Modeling (ISM) and its application in analyzing factors inhibiting implementation of Total Productive Maintenance (TPM)’, International Journal of Quality & Reliability Management, 32:3, 308–331. Randhawa, J.S., and Ahuja, I.S. (2017), ‘5S implementation methodologies: literature review and directions’, International Journal of Productivity and Quality Management, 20:1, 48–74.

Basic Lean Tools (VSM ­ and Workcell)

5

5.1 OVERVIEW ON PROCESS MAPPING AND VALUE STREAM MAPPING (VSM) A process map indicates the sequence of processes but does not indicate the details of value addition. VSM shows the steps involved in product manufacture from beginning to end where cost is incurred and value is added. It depicts all the steps from the receipt of customer order till the product is delivered to the customer, where the cost is incurred, and in turn where value is added. VSM quantitatively analyses the process sequence using time and inventory data.

5.1.1 Process Mapping • A process map indicates the sequence of process steps. • It qualitatively analyzes the process steps which add value and those that do not add value. • It helps to understand the process boundaries. • It enables recognizing the present status of process steps.

5.1.1.1 Types ­

DOI: 10.1201/9781003190332-5

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34  Lean Manufacturing Detailed Process Map It indicates all process steps with inputs and outputs. All process steps should be depicted. Need for Process Maps • Complete process sequence should be analyzed • Problem diagnosis and training tool should be used • Improvement areas should be identified • Qualitative analysis of process maps to enable waste identification should be undertaken

5.1.2 VSM • VSM denotes logically the activities needed for transforming raw material to product in line with customer requirements. It includes those activities that add value by consuming resources. • It provides an understanding of value flow. • It is based on the Supplier Input Process Output Customer (SIPOC) cycle. • The SIPOC cycle is triggered by customer requirements. • It includes the current state and the future state. • It includes three parts (the SIPOC cycle, process attributes, and timeline).

5.1.2.1 General VSM Scheme VSM analyzes the process stream from the value perspective based on time and inventory data. It helps to understand those activities that add value to the customer and those that do not add value.

5.1.2.2 Guidelines for Drawing VSM • • • • •

Selection of product family in such a way that tasks are manageable VSM should not be drawn for multiple product lines Both material and information flow should be mapped Data collection should be done in multiple shifts Data should be collected and plotted in the process attributes box

5  •  Basic Lean Tools (VSM and Workcell)  35 Production control Supplier

Customer Production Supervisor

Process C/T C/O AT UT

/t C/T

­FIGURE 5.1  Format of VSM

5.1.3 VSM Format The format of VSM is shown in Figure  5.1. As shown, VSM consists of three parts: the SIPOC cycle, process attributes, and timeline. The SIPOC cycle includes activities from receipt of customer order, request initiation to supplier, supplier supplying material which forms the input, and the output delivered to customer. The process attributes box includes the first row with the process name, the second row with operators, the third row with cycle time, the fourth row with changeover time, the fifth row with available time, and the sixth row with uptime. Inventory ( WIP) is represented between processes. The Raw Material Inventory (RMI) is represented between supplier and process 1. The Finished Goods Inventory ( FGI) is represented between the last process and the customer. Timeline is plotted below the process attributes box. The bottom segment of the timeline represents cycle time and the top segment indicates inventory being converted to timescale. The significance of the timeline is that it facilitates the calculation of lead time. The format of VSM can be understood and followed while drawing value stream maps.

36  Lean Manufacturing

5.2 VSM TERMINOLOGIES AND DATA TYPES (OBSERVATION/ MEASUREMENT, COMPUTATION DATA) 5.2.1 Data in VSM 5.2.1.1 Observation Based • • • •

Shift time: Time available per shift (8 hours or 8.5 hours) Processes Number of operators Inventory (units) ­

5.2.1.2 Measurement Based • Cycle time: Elapsed time between one part coming off the process and the next part entering the process • Changeover time: Time for changing over from one product variant to another

5.2.1.3 Computation Based • Available time: It is the difference between shift time and allowances • Uptime: The proportion of time the machine is running • Inventory (time scale) = inventory (units) to daily production Significance of inventory conversion to timescale To understand the magnitude of inventory and facilitate the calculation of lead time • Lead time = cycle time of all processes + inventory (timescale) • Takt time = It is the ratio of available time to customer demand It is the time needed to complete an activity in line with customer demand. Takt time calculation Shift time = 8.5 hours = 510 minutes Available time = 510 − 60 minutes = 450 minutes (after subtracting breaks) Customer demand = 150 parts/day Takt time = 450/150 = 3 minutes Cycle time of all processes must be well within the takt time.

5  •  Basic Lean Tools (VSM and Workcell)  37

5.3 CONSTRUCTION STEPS OF VALUE STREAM MAPS 5.3.1 Analysis of Current State VSM • The first step is to analyze which activities add value and which do not. Then customer requirements need to be understood in terms of quantity and schedule. The customer wants an exact supply of products. Then supplier capabilities and constraints need to be considered and accordingly the economic quantity to be supplied is calculated. • The present inventory/ WIP needs to be measured and converted to timescale. • Then takt time needs to be calculated and the cycle time compared with the takt time. Those processes whose cycle time are more than the takt time are considered to be bottlenecks. Appropriate actions need to be taken to bring cycle time in line with the takt time. • Then continuous flow should be ensured and, to the extent possible, it should be made single-piece flow. • Line balancing should be done to ensure that cycle times of all processes are closer to each other, thereby avoiding waiting.

5.3.2 Construction of VSM Customer demand needs to be captured. A complete walk-through of Gemba (shopfloor) should be done to recognize principal processes. Basic production processes need to be captured and mapped. Appropriate data to be gathered should be defined. This is followed by collection and mapping the data. Supplier-related details should be documented in terms of quantity to be supplied. Then information flow should be mapped. As lean tools focus on transformation from a push to a pull system, points should be located where the material is being pushed.

5.4 VSM ILLUSTRATION AND CASE STUDY The Current State Map (CSM) is shown in Figure 5.2. As shown, the product line includes six processes. The customer places an order and in turn the

38  Lean Manufacturing supplier supplies the raw material and production happens in a particular sequence. The inventory between processes with RMI and FGI is indicated. The number of operators, cycle time, changeover time are indicated with AT and UT. The timeline is represented below the processes attributes box. Cycle time data are indicated in the below segment and the inventory being converted to timescale is indicated in the top segment of the timeline.

5.4.1 VSM Case This section presents the case of VSM. The CSM provides an idea of the present scenario of manufacturing processes and is shown in Figure 5.2. Data parameters are represented in CSM. The CSM includes three parts: the SIPOC cycle, the process attributes box, and the timeline. As shown, CSM includes five processes ( P1–P5). For every process, cycle time, changeover times are measured; AT and UT are computed; inventory (RMI, Work in Process (WIP), and FGI) are observed and indicated. The bottom segment of the timeline indicates the cycle time and the top segment includes the inventory converted to timescale. Next, the lead time has to be found. The future state map is the improved scenario of manufacturing processes. It is shown in Figure 5.3 and includes the following improvements:

­FIGURE 5.2 

Current State Map

5  •  Basic Lean Tools (VSM and Workcell)  39

­FIGURE 5.3 

Future State of VSM

• SMED is implemented in the first process to reduce changeover time • 5S is implemented in the third and fifth processes. The third element of 5S is focused where workplace cleanliness has been focused • TPM implementation is focused wherein breakdown data has been studied and OEE (Overall Equipment Effectiveness) improvement has been focused • Because of the implementation of improvement actions, inventory and lead time get reduced.

5.5 VARIANTS OF VSM (ADVANCED MODELS OF VSM) Variants of VSM, which are advanced models of VSM, are discussed as follows: Procurement VSM (P-VSM) It is a variant of VSM applied for purchasing activities (Jing et al., 2020). The tool had been proposed from the viewpoint of procurement tasks generating

40  Lean Manufacturing value and then applying for enhancement of procurement process of manufacturing firms. P-VSM indicates Value Added (VA) and Non Value Added (NVA) activities during the procurement cycle. It helps in recognizing NVA parts, wastes, and delays in procurement tasks. Ultimately, this variant of VSM enhances procurement process efficiency. Ergo VSM It is a variant of VSM contributed by Rother and Shook (Arce et al., 2018). This variant of VSM enhances ergonomic aspects without any impact on production performance. It is used to assess physical and organizational ergonomic risk factors along with lean parameters in the assembly process. Sustainable VSM It is a variant of VSM that visualizes and evaluates sustainable performance (Brown et al., 2014). It amalgamates VSM with metrics to assess environmental impacts and societal wellbeing (Brown et  al., 2014). The traditional VSM approach does not consider environmental and societal performance as it investigates economics of product line with reference to time and inventory data. It has to be incorporated with environmental and societal performance to evaluate manufacturing operations from the sustainability viewpoint. Sustainable VSM includes sustainability metrics to view sustainable performance. Environmental metrics include process water, raw material usage, and energy consumption.

5.5.1 eVSM 5.5.1.1 Scope of eVSM Software The eVSM software module enables digital VSM and drawing and analyzing value stream maps.

5.5.1.2 Steps in eVSM Software It helps to map and improve mixed model value stream maps. It uses electronic templates for capturing the existing state of manufacturing processes. Then value stream maps are analyzed to compute lean metrics. “What-Ifs” can be done thereafter to explore improvement ideas. This is followed by prioritization of improvements based on an impact matrix. Then the desired state of processes is designed and the implementation plan is designed. A sample value stream map drawn in eVSM is shown in Figure 5.4.

F­ IGURE 5.4 

Value Stream Map (eVSM)

5  •  Basic Lean Tools (VSM and Workcell)  41

42  Lean Manufacturing

5.6 WORKCELL It is a productive grouping of machinery/equipment, tooling, trained personnel involved in producing similar products. The core objectives of the workcell are to ensure minimum people movement, minimal material movement, setup time reduction, effective space utilization. The steps of a workcell can be referred to in the literature (Gopalakrishnan, 2010). Part family denotes the group of parts having similar design attributes/ manufacturing attributes. The broad steps are: Part family selection, process finalization, selection of machinery, tools, jigs/fixtures, layout design, line balancing, manpower selection, quality standards formulation, automated testing. Problems in modifying existing product/process layout to cellular layout are: • • • •

Operators’ reluctance to work on multiple machines Fear of losing jobs and employee resistance Capital investment in machinery and tooling Training of employees

5.6.1 Implementation Steps of a Workcell • Methods for grouping of parts into the part family include visual inspection and Production Flow Analysis (PFA). Visual inspection is recommended for less complex parts. PFA is suggested for relatively complex parts where grouping is based on dedicated algorithms • Process finalization is based on deciding the manufacturing process with appropriate process parameters • Machinery has to be selected with consideration of process capability, maintenance aspects, special conditions. Then production tooling has to be selected with the consideration of universal tooling and tooling with QCO • The facility layout has to be designed with minimal wastes based on line balancing concepts. This helps minimize cycle time variations

5  •  Basic Lean Tools (VSM and Workcell)  43 • Manpower has to be selected with skill considerations pertaining to the activities. Manpower selection should be done based on customer demand. Man machine chart should be prepared • Workforce must have the willingness to work on multiple machines. Man machine charts need to be developed to facilitate the optimal allocation of workforce • Then production control system has to be designed considering the above-mentioned aspects. The system may be designed in line with external or internal customer demand • Production control system design (Gopalakrishnan, 2010): For directly supplying parts to the customer based on customer demand (external request) For supplying parts to inhouse assembly (internal request) For supplying parts as spares (internal or external customer request) • Testing to ensure trial run to observe any kind of problems and to proceed with actual implementation. Then a trial run has to be done to check the practical feasibility of the designed cell, which is when Cross-Functional Teams (CFTs) must be resolved • Standardization of parameters and measures to ensure constant productivity

5.7 CASE ON LEAN TOOLS SELECTION This study presents the selection of four primary or basic tools of lean manufacturing (5S, TPM, VSM, workcell). The selection of appropriate lean tools can be done based on lean parameters such as inventory, cycle time. Factors critical to lean parameters such as inventory, cycle time, takt time should be considered. The tool which is critical to lean parameters need to be focused. Based on these perspectives, the right lean tool needs to be selected. Alternatively, lean tools selection can be formulated as a decision-making problem with multiple lean criteria. This study focuses on the selection of lean tools as an Multi-Criteria Decision Making (MCDM) problem. Four lean tools are considered as alternatives: 5S, TPM, VSM, workcell. The governing criteria include streamlined processes, customer satisfaction, value addition, financial benefits, flexible workforce, QCO, project duration, takt time compliance, inventory reduction.

44  Lean Manufacturing Fuzzy Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) is used as a solution methodology. The procedural steps of fuzzy TOPSIS are as follows (Wang and Lee, 2009): Step#1: Establishing a fuzzy decision matrix with the help of experts’ inputs for alternative ratings and criteria weights. Suppose “m” ­ alternatives [a1 a2 a3 … am] (m ­ = 1, 2 … q) are computed against “n” ­ criteria [C1 C2 C3 … Cn] (n­ = 1, 2 … r). The alternative ratings and criteria weights of each expert EPk where k = 1, 2, 3 … k is represented by W = Wijk (m ­ = 1, 2 … q, j = 1, 2…. r, k = 1, 2 … k). Step#2: Computation of average fuzzy ratings for alternatives. For instance, the input data gathered from “k” ­ experts are in Triangular Fuzzy Numbers (TFNs) = (u­ k, vk, wk) where k = 1 to k, the average fuzzy rating is given by r = (u, v, w) where

k k 1 k u = min(u), v = ∑ vk , w = max(w) k k k k=1

(5. ­ 1)

Step#3: The fuzzy decision matrix is transformed into a fuzzy normalized matrix “N” using equations 5.2 and 5.3: u v w  n mn =  mn+ , mn+ , mn  +  wn wn wn 

(5.2) ­

where w+j = Max( wmn ) – for beneficial criteria  u− u− u−  and n mn =  j , j , j   wmn vmn umn 

­ (5.3)

where w −j = Min( wmn ) – for non-beneficial criteria Step#4: Constructing a weighted normalized matrix (W) ­ Step#5: Calculating the Fuzzy Positive Ideal Solution (FPIS) and the Negative Ideal Solution (FNIS) by considering maximum and minimum values of each column of matrix W for benefit criteria and just opposite for cost criteria. Step#6: Calculating the Euclidean distance for each alternative from FPIS i.e. d m+ and FNIS i.e., d m− . Step#7: Computation of Closeness coefficient “CCm ” using equation 5.4. CCi =

d m− (d + dm− ) + m

(5.4) ­

5  •  Basic Lean Tools (VSM and Workcell)  45 where 0 < CCm < 1 Step#8: Prioritizing the alternatives using the closeness coefficient. The alternative possessing closeness coefficient CCi nearer to 1 is observed to be the best alternative. Expert inputs have been obtained using scales for weights and ratings as shown in Table 5.1 (Wang and Lee, 2009). Inputs have been obtained from three experts of an automotive component manufacturing organization. Based on expert opinion, computations have been done and the ranking of lean tools is obtained. Table 5.2 presents expert inputs for lean tools with respect to some criteria and Table 5.3 presents an excerpt of fuzzy inputs. Then the fuzzy inputs are aggregated and normalized. Table 5.4 presents weighted normalized inputs. Table 5.5 depicts ranking of lean tools with respect to closeness coefficient. The ranking of lean tools is VSM > 5S > TPM > workcell. Based on the ranking, tools are subjected to implementation. VSM has been planned for ­first-level implementation.

5.8 SUMMARY This chapter presents the details of a process map. The significance of VSM, data parameters, format have been discussed with a case study. Variants of VSM and the scope of eVSM software have been presented and workcell and the implementation plan have been discussed. A case study on tools selection has been presented.

­TABLE 5.1  Linguistic Terms for Importance Weights and Performance Ratings IMPORTANCE WEIGHTS LINGUISTIC TERMS

FUZZY NUMBER

Very low (VL) Low (L) ­ Medium low (ML) Medium (M) ­ Medium high (MH) High (H) ­ Very high (VH)

(0, 0, 0.1) (0, 0.1, 0.3) (0.1, 0.3, 0.5) (0.3, 0.5, 0.7) (0.5, 0.7, 0.9) (0.7, 0.9, 1) (0.9, 1, 1)

PERFORMANCE RATINGS LINGUISTIC TERMS Very poor (VP) Poor (P) ­ Medium poor (MP) Fair (F) ­ Medium good (MG) Good (G) ­ Very good (VG)

FUZZY NUMBER (0, 0, 1) (0, 1, 3) (1, 3, 5) (3, 5, 7) (5, 7, 9) (7, 9, 10) (9, 10, 10)

VALUE ADDITION

FINANCIAL BENEFITS

FLEXIBLE WORKFORCE

F

Work cell

MG MG

G

MG

G

MG G

VG

TPM

VSM

MG

MG G

H

5S

VH

H

Weight

G

H

G

G

H

VG

G

MG F

VG MG

VG

MG

MG MG

MH H

MG MG F

MG F

H

MG F

G

MG F

G

VH

H

MG G

G

MG F

G

H G

VH

MG MG

MG G

MG G

MG G

H

MG MG G

MG G

VH

MG G

G

G

H

EX.1 EX.2 EX.3 EX.1 EX.2 EX.3 EX.1 EX.2 EX.3 EX.1 EX.2 EX.3 EX.1 EX.2 EX.3

CUSTOMER SATISFACTION

Expert Inputs for Lean Tools with Respect to Criterion

SYNCHRONIZED PROCESSES

­TABLE 5.2  PROJECT DURATION

TAKT TIME COMPLIANCE

INVENTORY REDUCTION

H

H

G

G

H

G

G VG

VH

H MG G

H

VG

G MG MG G

G

VH

H

VG

H

VH

G

MG

VG

MG G

MG G

MG MG G

VG

MG G

MG MG G MG MG MG G G

MG MG MG G

VG

H

MG MG F

MG MG F

MG F

VH

EX.1 EX.2 EX.3 EX.1 EX.2 EX.3 EX.1 EX.2 EX.3 EX.1 EX.2 EX.3

QUICK CHANGEOVER

46  Lean Manufacturing

Weight 5S TPM VSM Work cell

EX.1

EX.2

EX.3

SYNCHRONIZED PROCESSES

Excerpt of Fuzzy Inputs

(0.7, 0.9, 1) (0.9, 1, 1) (0.7, 0.9, 1) (5, 7, 9) (7, 9, 10) (5, 7, 9) (5, 7, 9) (7, 9, 10) (5, 7, 9) (9, 10, 10) (7, 9, 10) (7, 9, 10) (3, 5, 7) (5, 7, 9) (5, 7, 9)

TABLE 5.3 EX.2

EX.3

(0.9, 1, 1) (0.7, 0.9, 1) (0.7, 0.9, 1) (7, 9, 10) (7, 9, 10) (5, 7, 9) (5, 7, 9) (3, 5, 7) (5, 7, 9) (7, 9, 10) (7, 9, 10) (9, 10, 10) (7, 9, 10) (5, 7, 9) (3, 5, 7)

EX.1

CUSTOMER SATISFACTION

EX.2

EX.3

(0.7, 0.9, 1) (0.5, 0.7, 0.9) (0.7, 0.9, 1) (3, 5, 7) (5, 7, 9) (5, 7, 9) (5, 7, 9) (3, 5, 7) (5, 7, 9) (9, 10, 10) (7, 9, 10) (9, 10, 10) (5, 7, 9) (3, 5, 7) (5, 7, 9)

EX.1

VALUE ADDITION

5  •  Basic Lean Tools (VSM and Workcell)  47

(0.35, 0.716, 1) (0.35, 0.778, 1)

(0.21, 0.653, 1)

(0.21, 0.591, 0.9)

(0.49, 0.871, 1) (0.49, 0.871, 1)

FNIS (0.21, 0.591, 0.9)

FPIS

Work (0.21, 0.591, cell 0.9)

VSM (0.49, 0.871, 1) (0.49, 0.871, 1)

TPM (0.35, 0.716, 1) (0.21, 0.591, 0.9)

5S

CUSTOMER SATISFACTION

Weighted Normalized Inputs

SYNCHRONIZED PROCESSES

­TABLE 5.4  FINANCIAL BENEFITS

(0.15, (0.35, 0.5278, 0.778, 0.9) 0.9) (0.15, (0.35, 0.528, 0.9) 0.716, 0.9) (0.35, (0.35, 0.806, 1) 0.778, 1) (0.15, (0.35, 0.528, 0.9) 0.717, 0.9) (0.35, (0.35, 0.806, 1) 0.778, 1) (0.15, (0.35, 0.528, 0.9) 0.7166, 0.9)

VALUE ADDITION

(0.35, 0.778, 1) (0.49, 0.871, 1) (0.21, 0.591, (0.21, 0.591, 0.9) 0.9)

(0.35, 0.778, 1) (0.49, 0.871, 1) (0.21, 0.591, (0.35, 0.9) 0.717, 1)

(0.35, 0.778, 1) (0.21, 0.591, 0.9)

(0.35, 0.778, 1) (0.21, 0.591, 0.9) (0.21, 0.365, 0.6) (0.21, 0.3, 0.429) (0.21, 0.365, 0.6) (0.233, 0.442, 1) (0.21, 0.3, 0.429)

(0.233, 0.442, 1)

(0.35, 0.56, 1)

(0.35, 0.56, 1)

(0.35, (0.35, 0.608, 1) 0.609, 1) (0.35, 0.483, (0.35, 0.483, 0.714) 0.714)

(0.35, 0.483, (0.35, 0.483, 0.714) 0.714) (0.35, (0.35, 0.609, 1) 0.609, 1)

(0.35, 0.609, 1)

(0.35, 0.609, 1)

FLEXIBLE QUICK PROJECT TAKT TIME INVENTORY WORKFORCE CHANGEOVER DURATION COMPLIANCE REDUCTION

5 • Basic Lean Tools (VSM and Workcell) TABLE 5.5 LEAN TOOL 5S TPM VSM Work cell

49

Ranking of Lean Tools D+

D−

CC

RANK

0.745498 1.129968 0.700772 1.217421

1.143027 0.726202 1.127835 0.657028

0.605249 0.391237 0.616773 0.350518

II III I IV

REFERENCES Arce, A., Romero-Dessens, L.-F., and Leon-Duarte, J.A. (2018), ‘Ergonomic value stream mapping: a novel approach to reduce subjective mental workload’, in R.H.M. Goossens (ed.), Advances in Social  & Occupational Ergonomics, Advances in Intelligent Systems and Computing, 307–317, DOI: 10.1007/978-3-319-60828-0_31 Brown, A., Amundson, J., and Badurdeen, F. (2014), ‘Sustainable value stream mapping (Sus-VSM) in different manufacturing system configurations: application case studies’, Journal of Cleaner Production, 85, 164–179. Gopalakrishnan, N. (2010), Simplified Lean Manufacture – Elements, Rules, Tools and Implementation, PHI Learning Private Limited. Jing, S., Hou, K., Yan, J., Ho, Z.-P., and Han, L. (2020), ‘Investigating the effect of value stream mapping on procurement effectiveness: a case study’, Journal of Intelligent Manufacturing, 32, 935–946. Wang, T.C., and Lee, H.D. (2009), ‘Developing a fuzzy TOPSIS approach based on subjective weights and objective weights’, Expert Systems with Applications, 36, 8980–8985.

Supporting Lean Tools and Concepts

6

6.1 SCOPE OF SUPPORTING TOOLS Lean implementation starts with primary tools. Secondary tools augment primary tools in the implementation. Secondary tools enable recognizing areas of further studies, recognize causes for the problem, enable communication, and so on. In many real-life industrial applications, primary tools have to be supported with secondary tools for implementation. For example, Value Stream Mapping ( VSM) implementation necessitates the implementation of secondary tools such as Poka yoke, SMED, Just In Time (JIT), Kanban, and so on.

6.2 DESCRIPTION OF CORE SUPPORTING TOOLS (POKA YOKE, KANBAN, AUTONOMATION, VISUAL COMMUNICATION, AND SMED) This section presents the details of supporting or secondary tools of lean manufacturing.

DOI: 10.1201/9781003190332-6

51

52  Lean Manufacturing

6.2.1 Poka Yoke It is a prevention approach that enables operators not to make any mistakes during operation. Following criteria should be fulfilled: • Identification of out-of-control process • Admitting that humans commit mistakes • Realizing that solutions are inexpensive and are based on common sense Examples include sensors, fouling pins, contoured locators, ­self-aligning parts It is the approach of manufacturing products with close to zero defects. It is in line with the principle that defects are eliminated by performance regulation in a way that the product does not have defects. It employs sensors that are fitted in processing equipment to monitor and track errors. The system detects errors before manufacturing technology produces defective products (Mohan Prasad et  al., 2020). It facilitates detection and avoidance of abnormal conditions in the manufacturing process to prevent defective products. Solutions as a part of Poka yoke must be logical and cost-effective. It is a significant secondary lean tool which has several applications in industrial studies. Historically, this lean secondary tool is adopted in jigs & fixture mistake proofing.

6.2.2 Kanban • It is a Japanese term that implies an instruction card • It is a manual pull device that facilitates efficient parts transfer • It is used in a pull manufacturing system Governing rules • No production/withdrawal without a Kanban • No change in quantity in production and withdrawal • Part production based on priority order of Kanban • Kanban does not permit defective parts

6.2.2.1 Functions The Kanban card facilitates inventory function in terms of streamlining the inventory between processes. Production functions indicate the production

6  •  Supporting Lean Tools and Concepts  53 quantity to be produced. Visibility functions enable visual communication in terms of indication and displays with signal mechanism. Kanban is a signal mechanism and provides signals to regulate inventory, production, and visual information and communication. The objective is to pull the parts when needed to monitor and regulate in-process inventories. It is a Japanese term meaning card. The number of Kanbans indicates the maximum inventory of a product and must be as small as possible (Matzka et al., 2012). These systems were originally developed in Japan to deal with multi-stage manufacturing systems. They operate on pull principles. Customer demand is communicated upward stage by stage (Simic et al., 2019). Based on functions, they are categorized as withdrawal (transportation) Kanban and production Kanban. Finding the number of kanbans is a critical aspect in a JIT or a lean system to minimize in-process inventory and to deal with product shortage.

6.2.3 Autonomation • It is an automatic mechanism working based on signals to indicate the status of any machine or any other entity for measurement. It is a fully automatic mechanism with light and/or sound signals. It is very significant in the context of an Industry 4.0 system which is governed by signal mechanism. • The green signal denotes routine state, the red signal indicates problem with machine tools, and the yellow signal indicates quality problem. In the context of Industry 4.0, sensor data based on Internet of Things (IoT) should be linked as a part of autonomation.

6.2.4 Visual Communication It is a powerful technique in the context of a lean system. In the industry shop, visual boards are installed that depict key data in terms of shift target, quantity produced, and so on. Visual information enables the team to recognize the project plan, attainment, and goals. The mechanism can be supported on a computer, electronic board, or other visual media.

6.2.4.1 Visual Management It is a holistic approach enabling visual information to facilitate the team and individuals to gain better insights on their role and contribution. It facilitates identification of bottlenecks and enhances operational transparency.

54  Lean Manufacturing General criteria to be considered are empowerment of team, simple system, visual depiction of process with monitoring parameters. Functions are transparency, discipline, Continuous Improvement (CI), shared ownership, simplification, and unification (Filho Felipe et al., 2018).

6.2.5 SMED • It is an approach that aims at simplifying machine setups • This approach facilitates reduction of cycle time and lead time. It can be enabled by usage of relevant jigs, fixtures, dies, molds to avoid changeovers • Exchange of dies needs to be enabled to support product variants. Exchange time between setups must be lesser to contribute to lead time reduction SMED • It is an effective tool to minimize changeover times or setup time by transforming the steps done during machine stoppage (internal tasks) into steps with machine operating conditions (external tasks) • The approach aims at analyzing and reducing setup times with the goal of setup time reduction from hours to minutes. It reduces setup times with increase in manufacturing costs • It leads to enhanced productivity. It improves flow and enhances efficiency (Haddad et al., 2021) It is used to transform internal to external operations. SMED aims at reduction of duration of external operations (Amrani and Ducq, 2020) SMED facilitates Quick Change Over (QCO). It facilitates quick change of setups. As lean system facilitates process flexibility, exchange between setups is enabled using SMED. A lean system can facilitate manufacture of few product variants which can be done through faster exchange of setups.

6.3 OPTIMIZED PRODUCTION TECHNOLOGY, LEVELED PRODUCTION, AND ENTERPRISE RESOURCE PLANNING The details are presented in the following subsections.

6  •  Supporting Lean Tools and Concepts  55

6.3.1 Optimized Production Technology It is a proprietary scheduling system based on computer software to take care of shopfloor scheduling as the critical problem faced by manufacturing firms. The objective of Optimized Production Technology (OPT) is to schedule bottleneck capacity in an effective way. It includes preparation, plant, and bottleneck analysis. OPT deals with key problems of handling bottlenecks and enhances profitability by concurrent throughput improvement.

6.3.2 Heijunka (Leveled ­ Production) The details of Heijunka are presented as follows (Koide and Iwata, 2007): • In this system, multiple products in a process are produced at the same time; thus production and item type are averaged as the successive process pulls from prior process • For averaging quantities and item types produced, time period for averaging is found first • Scheduling may be on a weekly, daily, or per unit basis • The period of scheduling may be found based on needs of the successive process and other factors • Unwanted inventory is not accumulated and the workforce needed for preceding operations is reduced

6.3.2.1 Production Leveling Heijunka is the Japanese term for leveling of production. Heijunka eliminates muda, mura, and muri. Production leveling involves adapting manufacturing to variable demand conditions. Conventional manufacturing is unleveled whereas leveled production is incorporated with changeovers. Leveled production forms the basis for pull systems, minimized inventory, capital, and labor. Even in the context of a pull system, workstations may not be synchronized. One workcenter may go faster than the other, which creates inventory between workstations, in turn affecting lead time. Production leveling contributes to synchronized workcenters.

6.3.3 Enterprise Resource Planning It is an approach for effective planning and the control of resources. It amalgamates all divisions and application modules into a single computer system

56

Lean Manufacturing

to serve each department requirements from a central repository. Enterprise Resource Planning (ERP) is based on push principles wherein it relies on forecasts and historical data. Lean is based on a pull system where products are produced in line with customer demand.

6.3.3.1 ERP and Lean Integration ERP systems have a goal used in coordination with lean concepts Lean is based on a pull system and products are produced based on customer demand ERP is based on a push concept, where products are produced based on forecasted demand (Halgeri et al., 2008) Increasing competition has contributed to the integration of ERP and lean applications. ERP systems are based on IT with the focus on amalgamating different business functions. Lean manufacturing enables value-added activities by elimination of wastes and NVA (Non-Value-Added) activities (Iris and Cebeci, 2014). ERP deployment can act as a catalyst for deployment of lean practices. VSM and standardized work enable the process development for ERP deployment (Powell et al., 2013).

6.4 SUMMARY This chapter presents the scope of secondary tools. A description of the core supporting tools Poka yoke, Kanban, autonomation, visual communication, and SMED have been provided. Details of concepts OPT, Heijunka, and ERP have been presented. Insights for ERP and lean integration have also been discussed.

REFERENCES Amrani, A., and Ducq, Y. (2020), ‘Lean practices implementation in aerospace based on sector characteristics: methodology and case study’, Production Planning & Control, 31:16, 1313–1335, DOI: 10.1080/09537287.2019.1706197 Filho Felipe, A.B.S., Pontes Heráclito, L.J., Albertin, M.R., de Lima Raphael, L.M., & Moraes Thais, d.C. (2018). ‘Application of visual management panel on an airplane assembly station’, International Journal of Productivity and Performance Management, 67:6, 1045–1062, Doi: http://dx.doi.org/10.1108/IJPPM-09-2016-0189

6 • Supporting Lean Tools and Concepts

57

Haddad, T., Shaheen, B.W., and Németh, I. (2021), ‘Improving overall equipment effectiveness (OEE) of extrusion machine using lean manufacturing approach’, Manufacturing Technology, 21:1, 56–64. Halgeri, P., Pei, Z.J., Iyer, K.S., Bishop, K., and Shehadeh, A. (2008), ‘ERP Systems Supporting Lean Manufacturing: A Literature Review’, Proceedings of the 2008 International Manufacturing Science and Engineering Conference MSEC2008 October 7–10, 2008, Evanston, IL. Iris, C., and Cebeci, U. (2014), ‘Analyzing relationship between ERP utilization and lean manufacturing maturity of Turkish SMEs’, Journal of Enterprise Information Management, 27:3, 261–277. Koide, K., and Iwata, T. (2007), ‘Kaizen through Heijunka Production (Leveled Production),’ SAE Technical Paper 2007-01-3886, DOI: 10.4271/2007-01-3886. Matzka, J., Mascolo, M.D., and Furmans, K. (2012), ‘Buffer sizing of a Heijunka Kanban system’, Journal of Intelligent Manufacturing, 23, 49–60. Mohan Prasad, M., Dhiyaneswari, J.M., Jamaan, J.R., Mythreyan, S., and Sutharsan, S.M. (2020), ‘A framework for lean manufacturing implementation in Indian textile Industry’, Materials Today: Proceedings, 33:7, 2986–2995. Powell, D., Alfnes, E., Strandhagen, J.O., and Dreyer, H.C. (2013), ‘The concurrent application of lean production and ERP: towards an ERP-based lean implementation process’, Computers in Industry, 64:3, 324–335. Siaudzionis Filho Felipe, A.B., Pontes Heráclito, L.J., Albertin, M.R., de Lima Raphael, L.M., and Moraes Thais, d.C. (2018), ‘Application of visual management panel on an airplane assembly station’, International Journal of Productivity and Performance Management, 67:6, 1045–1062, DOI: 10.1108/IJPPM-09-2016-0189 Simic, D., Svircˇevic, V., Corchado, E., Calvo-Rolle, J.L., Simic, S.D., and Simic, S. (2019), ‘Modelling material flow using the Milk run and Kanban systems in the automotive industry’, Expert Systems, DOI: 10.1111/exsy.12546

Project Selection and Training for Lean Implementation

7

7.1 IMPORTANCE OF PROJECT SELECTION Project selection is a vital step as the majority of projects (about 40%) fail due to improper project selection. Even the importance of project selection is not considered by certain organizations (Singh et al., 2021).

7.2 PROJECT SELECTION FOR LEAN IMPLEMENTATION As lean implementation is project driven, it is vital to evaluate and select projects compatible for Continuous Improvement (CI). Lean projects vary in terms of goals and complexity but have related risks (Singh et al., 2021). As many lean projects have certain benefits, key projects that provide maximum financial benefits to the organization have to be selected. Most projects involve multiple criteria and project selection problem is Multi-criteria decision making (MCDM) in nature. The selection of projects depends on multiple criteria inclusive of quantitative and qualitative criteria (Singh et al., 2021).

DOI: 10.1201/9781003190332-7

59

60  Lean Manufacturing ­TABLE 7.1 

Project Selection Criteria

CRITERION NUMBER C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C13 C14

CRITERION Pull production & streamlined process Project duration Technical feasibility Customer satisfaction New business avenues Return on investment Top management commitment Employee involvement Continuous training and education Process improvement Multi-skilled and flexible workforce Activity categorization Waste analysis Flexible setups

Selection of the appropriate projects is a key task as a part of CI activities. If the right project is not selected during the early phases, benefits cannot be attained and resource wastage might happen. Some of the guidelines for effective lean project selection are linkage of projects to organization goals, contribution of the project in terms of financial benefits, duration of the projects, governing criteria, project deliverables. Project selection should be done considering multiple criteria with defined goals. Based on the literature, brainstorming and a voting method are recommended with other MCDM methods (Trakulsunti et al., 2020). Project selection and prioritization is an essential step in lean deployment. The success of initial projects forms the motivation for lean implementation. Wrong project selection could lead to loss of interest among employees and management. It had been suggested to follow appropriate procedure for selection and prioritization of projects based on selection criteria (Antony et al., 2018). Table 7.1 presents concept selection criteria.

7.2.1 Case on Lean Project Selection ­ Criteria were identified from a literature study and presented to the academia and industrial experts. Based on their opinion, 14 criteria were selected

7  •  Project Selection and Training for Lean Implementation  61 for the lean concept selection process. The Fuzzy Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) (F-TOPSIS) method was employed to choose the best lean concept. The methodological steps of F-TOPSIS can be referred to from Section 5.7. Three lean concepts, namely, A1, A2 and A3, are analyzed with respect to 14 lean concept selection criteria. Table 7.2 presents the linguistic variables for ratings and weights ( Wang and Lee, 2009). Table 7.3 presents expert inputs for the relationship of various criteria with respect to alternative 1. Table 7.4 presents the importance of criteria with respect to three decision makers. Table 7.5 presents a fuzzy relationship matrix. The case study presents project selection for lean implementation with 3 alternative projects and 14 criteria. Three alternative projects are product lines involved in lean implementation. The best project to be selected is based on governing criteria. As the organization is in the process of lean implementation, projects need to be prioritized. Criteria are selected based on literature review and expert opinion. Expert opinion has been obtained and the F-TOPSIS approach has been used for prioritizing projects. The computational steps of F-TOPSIS are discussed using a case study. The study was carried out in an automotive component manufacturing organization. In this study, 14 criteria were taken into consideration for choosing the appropriate lean concept. Those 14 criteria were further evaluated to assess how the criteria influence one other. This criteria list was discussed with academia and industrial experts. From this survey, values were calculated and the criteria influence over one other was depicted. Initially the relationship between criteria values were obtained in linguistic form and then appropriate values were assigned to proceed with calculation. ­TABLE 7.2  Linguistic Variables for Ratings and Weights RATINGS LINGUISTIC VARIABLE

WEIGHTS

FUZZY NUMBER

Very poor (VP) Poor (P) ­ Medium poor (MP) Fair (F) ­ Medium good (MG)

(0, 0, 1, 2) (1, 2, 2, 3) (2, 3, 4, 5) (4, 5, 5, 6) (5, 6, 7, 8)

Good (G) ­ Very good (VG)

(7, 8, 8, 9) (8, 9, 10, 10)

LINGUISTIC VARIABLE Very low (VL) Low (L) ­ Medium low (ML) Medium (M) ­ Medium high (MH) ­ High (H) ­ Very high (VH)

FUZZY NUMBER (0, 0, 0.1, 0.2) (0.1, 0.2, 0.2, 0.3) (0.2, 0.3, 0.4, 0.5) (0.4, 0.5, 0.5, 0.6) (0.5, 0.6, 0.7, 0.8) (0.7, 0.8, 0.8, 0.9) (0.8, 0.9, 1, 1)

62  Lean Manufacturing ­TABLE 7.3  Expert Inputs for Alternative 1 with Respect to Different Criteria DECISION MAKER (DM) CONCEPT A1

­TABLE 7.4 

CRITERIA Pull production & streamlined process Project duration Technical feasibility Customer satisfaction New business avenues Return on investment Top management commitment Employee involvement Continuous training and education Process improvement Multi-skilled and flexible workforce Activity categorization Waste analysis Flexible setups

DM 1

DM 2

DM 3

VG MG G VG G VG G MG G VG G MG G G

G G VG G VG G MG G F G MG G G G

G MG G G G G G MG G G G MG MG MG

Importance Weights of the Criteria by Three Decision Makers DECISION MAKER (DM)

CRITERIA

DM 1

DM 2

DM 3

Pull production & streamlined process Project duration Technical feasibility Customer satisfaction New business avenues Return on investment Top management commitment Employee involvement Continuous training and education Process improvement Multi-skilled and flexible workforce Activity categorization Waste analysis Flexible setups

VH MH H H MH MH H M H VH H H MH M

H H MH VH H M MH MH M H H MH H ML

H MH H H H MH M H ML H VH H MH MH

7  •  Project Selection and Training for Lean Implementation  63 ­TABLE 7.5  Fuzzy Relationship Matrix A1

A2

C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C13 C14

C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C13 C14

DM 1

DM 2

DM 3

8, 9, 10, 10 5, 6, 7, 8 7, 8, 8, 9 8, 9, 10, 10 7, 8, 8, 9 8, 9, 10, 10 7, 8, 8, 9 5, 6, 7, 8 7, 8, 8, 9 8, 9, 10, 10 7, 8, 8, 9 5, 6, 7, 8 7, 8, 8, 9 7, 8, 8, 9

7, 8, 8, 9 7, 8, 8, 9 8, 9, 10, 10 7, 8, 8, 9 8, 9, 10, 10 7, 8, 8, 9 5, 6, 7, 8 7, 8, 8, 9 4, 5, 5, 6 7, 8, 8, 9 5, 6, 7, 8 7, 8, 8, 9 7, 8, 8, 9 7, 8, 8, 9

7, 8, 8, 9 5, 6, 7, 8 7, 8, 8, 9 7, 8, 8, 9 7, 8, 8, 9 7, 8, 8, 9 7, 8, 8, 9 5, 6, 7, 8 7, 8, 8, 9 7, 8, 8, 9 7, 8, 8, 9 5, 6, 7, 8 5, 6, 7, 8 5, 6, 7, 8

DM 1

DM 2

DM 3

7, 8, 8, 9 7, 8, 8, 9 5, 6, 7, 8 4, 5, 5, 6 7, 8, 8, 9 7, 8, 8, 9 8, 9, 10, 10 7, 8, 8, 9 5, 6, 7, 8 7, 8, 8, 9 5, 6, 7, 8 5, 6, 7, 8 5, 6, 7, 8 7, 8, 8, 9

5, 6, 7, 8 5, 6, 7, 8 7, 8, 8, 9 5, 6, 7, 8 4, 5, 5, 6 4, 5, 5, 6 7, 8, 8, 9 5, 6, 7, 8 4, 5, 5, 6 5, 6, 7, 8 4, 5, 5, 6 4, 5, 5, 6 4, 5, 5, 6 5, 6, 7, 8

7, 8, 8, 9 5, 6, 7, 8 4, 5, 5, 6 5, 6, 7, 8 7, 8, 8, 9 7, 8, 8, 9 5, 6, 7, 8 5, 6, 7, 8 5, 6, 7, 8 2, 3, 4, 5 5, 6, 7, 8 5, 6, 7, 8 5, 6, 7, 8 2, 3, 4, 5 (Continued )

64  Lean Manufacturing

A3

C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C13 C14

DM 1

DM 2

DM 3

5, 6, 7, 8 5, 6, 7, 8 5, 6, 7, 8 4, 5, 5, 6 5, 6, 7, 8 4, 5, 5, 6 5, 6, 7, 8 4, 5, 5, 6 7, 8, 8, 9 7, 8, 8, 9 7, 8, 8, 9 4, 5, 5, 6 7, 8, 8, 9 5, 6, 7, 8

7, 8, 8, 9 7, 8, 8, 9 4, 5, 5, 6 5, 6, 7, 8 7, 8, 8, 9 5, 6, 7, 8 4, 5, 5, 6 5, 6, 7, 8 5, 6, 7, 8 5, 6, 7, 8 4, 5, 5, 6 2, 3, 4, 5 5, 6, 7, 8 4, 5, 5, 6

5, 6, 7, 8 5, 6, 7, 8 5, 6, 7, 8 4, 5, 5, 6 5, 6, 7, 8 4, 5, 5, 6 5, 6, 7, 8 7, 8, 8, 9 5, 6, 7, 8 4, 5, 5, 6 5, 6, 7, 8 4, 5, 5, 6 5, 6, 7, 8 2, 3, 4, 5

Individual criteria weights were assigned to 14 lean concept selection criteria by decision makers. The values were assigned in the form of fuzzy numbers and so in order to find the best lean concept, these fuzzy ratings were normalized and averaged out with available three lean concepts which were carried out in further computational process. The individual criteria weightage with respect to three lean concepts are averaged to find the overall weightage of criteria. The fuzzy values are normalized with criteria weight and it is depicted in Table 7.6 as weighted normalized criteria. Table 7.7 depicts the ideal positive and negative distance values for 14 criteria with respect to three lean concepts A1, A2, and A3. The span of criteria to lean concepts was calculated to identify the most closely associated lean concept. Table  7.8 depicts the closeness coefficient index of three lean concepts with respect to 14 criteria. It is found that lean concept A2 lies with closeness coefficient value of 0.62 followed by A1 with 0.60 and A3 with 0.59. Thus, concept A2 is ranked as top most lean concept compared to other two lean concepts with respect to selection criteria. Based on the computations using the F-TOPSIS approach, projects are prioritized and subjected to implementation. The priority order of projects helps industry practitioners in implementing lean concepts.

C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C13 C14 A* A_

­TABLE 7.6 

0.49 0.275 0.2 0.49 0.35 0.16 0.2 0.2 0.088 0.49 0.308 0.25 0.22 0.044 0.49 0.044

0.6889 0.5025 0.3504 0.6889 0.6059 0.2736 0.4599 0.4158 0.3021 0.6889 0.4482 0.4818 0.3618 0.1269 0.6889 0.1269

0.7482 0.4964 0.3542 0.7482 0.6622 0.2898 0.5092 0.4891 0.3249 0.7482 0.4524 0.5621 0.3796 0.1378 0.7482 0.1378

1 0.9 0.513 1 0.9 0.456 0.81 0.81 0.9 1 0.8 0.81 0.72 0.32 1 0.32

WEIGHTED NORMALIZED FUZZY MATRIX A1

Weighted Normalized Criteria Matrix

0.35 0.275 0.22 0.28 0.22 0.176 0.2 0.2 0.1 0.14 0.35 0.2 0.25 0.044 0.35 0.044

0.6059 0.5025 0.4599 0.4648 0.511 0.3249 0.4788 0.4158 0.3763 0.4648 0.5893 0.4088 0.4757 0.1645 0.5893 0.1645

0.6612 0.4964 0.462 0.5481 0.539 0.3591 0.5561 0.4891 0.3591 0.5481 0.5481 0.4851 0.4599 0.1643 0.5481 0.1643

0.9 0.9 0.9 0.8 0.81 0.8 0.9 0.81 0.9 0.9 1 0.72 0.9 0.8 1 0.8

WEIGHTED NORMALIZED FUZZY MATRIX A2 0.35 0.275 0.25 0.28 0.25 0.2 0.16 0.16 0.088 0.28 0.308 0.1 0.2 0.05 0.308 0.05

0.5478 0.5025 0.5183 0.4648 0.4818 0.4047 0.3528 0.3969 0.318 0.5229 0.5229 0.3139 0.402 0.2021 0.5229 0.2021

0.6351 0.4964 0.4851 0.4872 0.5621 0.4473 0.4221 0.4422 0.3078 0.5742 0.522 0.3542 0.3942 0.1961 0.522 0.1961

0.9 0.9 0.9 0.8 0.81 0.8 0.72 0.81 0.72 0.9 1 0.54 0.72 0.8 1 0.8

WEIGHTED NORMALIZED FUZZY MATRIX A3

7  •  Project Selection and Training for Lean Implementation  65

C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C13 C14 SUM Projects

TABLE 7.7

0 0.226842971 0.443879582 0 0.120947647 0.512328231 0.276744166 0.295474996 0.408412018 0 0.269912412 0.238902784 0.362473158 0.67075782 3.826675784 A1

0.08768727 0.09279391 0.13045762 0.14189227 0.14049164 0.24214621 0.12216689 0.17529333 0.2262668 0.15231574 0 0.2140477 0.11645342 0.39217066 2.23418345 A2

FPIS

Ideal Positive and Negative Solution 0.091607 0.063667 0.070111 0.122978 0.119389 0.154073 0.215421 0.163552 0.267498 0.067104 0 0.330001 0.200843 0.32439 2.190634 A3

0.670758 0.468839 0.229758 0.670758 0.558114 0.159767 0.413627 0.396363 0.366987 0.670758 0.409187 0.442915 0.318654 0 5.776485 A1

0.426372 0.309782 0.268863 0.312612 0.311736 0.164417 0.3091 0.253695 0.178832 0.292517 0.392171 0.253858 0.280868 0 3.754823 A2

FNIS 0.370688 0.283458 0.278988 0.262457 0.289993 0.205465 0.175391 0.192104 0.106072 0.320818 0.32439 0.18938 0.189828 0 3.189034 A3

66  Lean Manufacturing

7  •  Project Selection and Training for Lean Implementation  67 ­TABLE 7.8  Closeness Coefficient Index CONCEPTS A1 A2 A3

D+ 3.826675784 2.234183454 2.190634481

D− 5.7764848 3.7548225 3.18903391

CCI 0.601519 0.626953 0.592794

RANK 2 1 3

7.3 TRAINING AND IMPLEMENTATION FOR LEAN Steps involved in training and implementation are discussed as follows: a. Formation of a dedicated team with lean leaders and associates A dedicated team has to be formed with management representatives who will coordinate lean implementation, and select lean leaders for planning various projects and lean associates to coordinate lean implementation



c. Formation of a training schedule and training leaders and associates A training schedule has to be formed for training the workforce at different levels: lean leaders, lean associates, shop workers



e. Formation of a project-wise team On identification of potential projects, a project-wise team has to be formed with coordinator and members from different divisions





g. Project implementation and review This is followed by implementing projects as per the plan. Based on the project scope, primary and secondary lean tools have to be ideated and implemented h. Computation of cost savings

68  Lean Manufacturing This has to be followed by cost savings by involving personnel from finance division.

7.4 LEAN IMPLEMENTATION LEVELS Lean implementation has to be followed by focusing on the following aspects (Gopalakrishnan, 2010):

1. The system has to be made stable by exploring the reasons for unstability. Appropriate actions should be taken to overcome the reasons for unstability and the system has to be made stable. 2. Once the system has been made stable, work standardization has to be achieved for ensuring consistency. Standard Operating Procedures (SOPs) and Standard Instructions (SIs) have to be focused in this regard. 3. Production has to be made pull in compliance with customer demand. A pull system facilitates the reduction of inventory.

5. The final level needs to be sustained through CI (Kaizen). Sustenance is a critical element of 5S.

7.5 SUMMARY This chapter presents the significance of project selection for lean deployment. A case of lean project selection is illustrated using an MCDM tool. Steps involved in training and implementation are presented with lean implementation levels.

7 • Project Selection and Training for Lean Implementation

69

REFERENCES Antony, J., Gupta, S., Vijaya Sunder, M., and Gijo, E.V. (2018), ‘Ten commandments of lean six sigma: a practitioners’ perspective’, International Journal of Productivity and Performance Management, 67:6, 1033–1044. Gopalakrishnan, N. (2010), Simplified Lean Manufacture – Elements, Rules, Tools and Implementation, PHI Learning Private Limited. Singh, M., Rathi, R., Antony, J., and Garza-Reye, J.A. (2021), ‘Lean six sigma project selection in a manufacturing environment using hybrid methodology based on intuitionistic fuzzy MADM approach’, IEEE Transactions on Engineering Management, DOI: 10.1109/TEM.2021.3049877 Trakulsunti, Y., Antony, J., Ghadge, A., and Gupta, S. (2020), ‘Reducing medication errors using LSS Methodology: a systematic literature review and key findings’, Total Quality Management & Business Excellence, 31:5–6, 550–568, DOI: 10.1080/14783363.2018.1434771 Wang, T.C., and Lee, H.D. (2009), ‘Developing a fuzzy TOPSIS approach based on subjective weights and objective weights’, Expert Systems with Applications, 36, 8980–8985.

Lean Performance Measurement

8

8.1 LEAN PERFORMANCE MEASURES ­ Appropriate performance measures of lean should be identified and analyzed. Some of the common performance measures include inventory, cycle time, changeover time, lead time, and value addition. These performance measures are basic measures. Performance measures contributed in research include indicators from different perspectives such as management, technology, employee, organization, and so on. Different solution methods are adopted in literature for analysis. Leanness is the comprehensive lean performance index with several indicators. Leanness measurement helps the organization to gauge its lean performance. It is a comprehensive measure for lean practices. Lean performance measurement needs to be done at regular time periods to monitor improvements in performance which help organizations to sustain in the competitive scenario.

DOI: 10.1201/9781003190332-8

71

72  Lean Manufacturing ­TABLE 8.1  Dimensions and Sub-Dimensions for Leanness Assessment DIMENSION Organizational hierarchy

­SUB-DIMENSIONS

Cultural transition Workforce with interchangeable tasks Management perspective Management commitment Management vision for lean practices Problem solving Kaizen approach adoption Quick problem solving Pull manufacturing ­Demand-driven manufacturing Inventory management Streamlined processes Value stream mapping adoption Analysis of seven wastes Waste and activity analysis Waste quantification Activity categorization (VA, NVA. NNVA) Employee Flexible workforce ­Multi-skilled workforce Manufacturing setups Flexible setups Lesser time for changing setups Visual controls Poka Yoke concepts Andon devices Product design Design for Manufacture and Assembly (DFMA) concepts Lean principles for product design Standardization Component standardization Adoption of Standard Operating Procedures (SOPs), Standard Instructions (SIs) Layout Organized layout Flexible layout Time management Takt time computation Scheduled activities Resource management Resource monitoring Resource allocation Quality management Usage of appropriate quality tools/techniques Zero defects Maintenance management OEE (Overall Equipment Effectiveness) monitoring and analysis Preventive maintenance adoption Technology management Incorporation of new technologies ­Technology-driven improvements

8  •  Lean Performance Measurement  73

8.2 ASSESSMENT APPROACHES 8.2.1 ­Multi-Grade Fuzzy Approach The leanness index of the organization is given by I which is the product of the overall assessment factor R and the overall weight W (Vinodh and Chintha, 2011). L .I . = W × R

(8.1) ­

Evaluation is split into five grades I = {10, 8, 6, 4, 2} 8–10 – Extremely lean ­6–8­ – Lean 4– 6 – Generally lean 2– 4 – Not lean