OEE for Operators.pdf

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SHOPFLOOR S E R I E S

O 1999 by Productivity, lnc

1\11 rights resenetl. No part of this book m y be reproduced or utilized in airy fonn or by any means, electronic or mccl~anical,including photocopying, recording, or by any inforomtion stonge and retrieval system, without permission in writing from the poblislicr. Additional copies of &is book and a learning package for leading a book study group arc ;w;~ilablerrom the publislrer. Discounts are a d a b l e for multiple copies through the Sales Department (800-394-6868). Address all other inquiries to: i'roductivit)., lnc. P.O. Box 13390 Portland OR 9721 3.0390 United States of Arnerica Teleplionc: 503-235-0600 I k : 503-235-0909 Email: [email protected] Cover by h'lnrk t;Veiirstei~t Cover illnstratioo by Gar) Ibgaglia Page design and composition by William Ii. Bn~nson,Typography Services Gmphics by Guy Buster, Lee Smith. and Hannah Borrrier Printed and botrnd by h,lalloy Lithographing, Inc. ill tire United Stales of Arnerica

Libra? of Congress Cataloging-in-Publicatiort Data O E E for operators : ovcrall equipment cffectiverress I created by the f'roductivity Developnient Team. 1'. c1n. Includes bil~liograplricalrerereoces. ISBN 1-56327-221-0 (dk. psper) 1. Ibtal productive mainteni~ace. 2. lrrdustrial equiprnerrt. 1. Productivity DeveIopment'Tcam (Productivity f'ress) TS192.032 1999 99-3532 658.?7-dc21 CIP

Publisher's Message Getting Started The Purpose o f This Book What This Book i s Based On Two Ways t o Use This Book How t o Get the M o s t Out o f Your Reading Overview o f the Contents

Chapter 1.About TPM and OEE Chapter Overview What Is TPM? What is OEE and Why Ls It Important? Quantity Over Time is Only Part of OEE Effectiveness Focuses on the Equipment, Not the Person The Purpose of Measurement Is Improvement The Role of t h e Shopfloor Team in Using OEE In Conclusion Summary Reflections

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CONTENTS

Chapter 2. Understanding EquipmentRelated Losses Chapter Overview Losses Reduce Overall Equipment Effectiveness Visualizing OEE and the Losses Availability Performance Quality

Availability: Downtime Losses Failures and Repairs Setup Time Other Losses to Avaiiabiiity

Performance: Speed Losses Reduced Operating Speed Minor Stoppages

Quality: Defect Losses Scrap and Rework Startup and Reduced Yield

In Conclusion Summary Reflections

Chapter 3. Measuring OEE Chapter Overview Closing the Feedback Loop Collecting OEE Data Defining What t o Measure Making Data Collection Simple

Processing OEE Data The OEE Calculation Storing OEE Data

Reporting OEE Results In Conclusion Summary Reflections

9 9 10 12

Chapter 4. Improving OEE Chapter Overview 5 Why Analysis Autonomous Maintenance Focused Equipment and Process Improvement Quick Changeover Stage 1: Separate Internal and External Setup Stage 2: Convert Internal Setup to External Setup Stage 3: Streamline All Aspects of Setup

ZQC (Mistake-Proofing) Poka-Yoke Systems

P-M Analysis In Conclusion Summary Reflections

Chapter 5. Reflections and Conclusions Chapter Overview Reflecting on What You've Learned Opportunities for Further Learning Conclusions Additional Resources on TPM, OEE, and Equipment-Related Losses Training and Consulting Packaged Education and Support Conferences and Public Events Newsletter Website

About the Productivity Development Team

Smoothly operating equipment is critical for inanufacturing today. Most processes use machines to add the value c~istornerspay for. In an environment that is more competitive than ever, factory machines have to work dependably to supply products \vhen the custo~iierneeds them. Yet factories eveqwliere are plagued with machine problems of one type or another. Tlie conipanies that are pulling ahead in the production race are those that understand their equipnient problems and take steps to eliminate them. The key to this understandiiig is overall equipment effectiveness. Overall equipment effectiveness (OEE) is a measure that shows how well the equipment is running. It indicates not just how many procluets tlie machine is turning out, but how much of the time it is actually working-and what percentage of the output is good quality. Because it reflects these three important things, OEE is an important indicator of tlie healtli of tlie equipment. Tlie condition of the equipment isn't just a maintenance issue anymore. In Total Productive Maintenance (TPM) approaches, equipment operators help prevent equipment problems through their knowledge and familiarity with the machines. Operators also monitor the machine conclitions used for calculating OEE. This book is intended to share basic learning that will help you participate effectively as your company applies OEE and begins to reduce equipment-related losses. Chapter 1 lays a foundation with basic definitions related to Total Productive Maintenance and OEE. You \sill learn why it is important to track effectiveness rather than effieiency..~hapker2 introduces the three elements of OEE and their connection to key types of equipment-related losses-problems and wastes that reduce a macliine's effeeliveness. This is a basic framework that can be adapted to measure and begin to improve equipment problems in many different industries." "'Tlie OEE calciilation and loss framework used in this Look relntes most directly to discrete parts menufacturers, ratlrer than process industries, wliicii face sliglrtlg diffcren! issues, For inore or1 ineasoremcot in process ind~~stries, sec Sozuki, cd., TFM in Process liidrrstries (Productivity, 1994).

PUBLISHER'S MESSAGE

Chapter 3 offers a step-by-step ovenliew of the process of doing the OEE calculatiori." One basic aspect is sliopfloor involvernent. It's important for date to be collected on tlie shop floor and turned into information for use on the shop floor-not confined to an ofice or i~iforniationdepartrnent. This cliapter also dcscrilies how to define what to measure and how to collect and process OEE data. It gives examples of different i~iforniationdisplays that OEE data can generate (computer software is helpful for this). Cliqitcr 4 ktalks about how to respond to OEE information to fix the problems. It introduces thc 5 Why nietlioil, autoriomous niaintenance, focused equipment iniprovement, quick changeover, niistake-proofing, and 1'-h4 analysis. Chapter 5 lielps you review your learning and suggests :additional resources for exploring key topics. It is imiioriant to remember as you read that this material is a general oricniation to a coniplex topic. Application and master). of overall equipment effecliseness often requires a deeper under. . r stancling of the production niechanistn I lie process of tising OEE is best supporfcd by experienced consultants and trainers who can help you tailor it. to your company's specific situation and address issues that may come up. 3

This book incorporates a number of features that will lielp you get the niost from it. Each cliapter begins with an ovenkw of tlie contents. Tlie book uses many illustrations to share inform.d t'lon and examples in a visual way. Icon sy~iibolsin the margin flag key points to reniember in each section. And "Take Five" questions built into the text provide a framework for applying wliat you've learned to your own situation. One of the niost effective ways to use this book is to read and cliscuss it nith other eniployccs in group learning sessions. We have deliberately planned the book so that it can be used this way, with chunks of information that can be covered in a series of short sessions. Each chapter includes reflection questions to stimulate group discussion. "Somc tmditior~al;ippro"clies to OLL use ;I two-part f o r n ~ ~ ~for l ; icaleiilati~igperformance thnt uses cycle time ;IS an elenient. Altlxn1g11the two-part for111111ayields infori~~ation tlmt III~IJ.be ii&l lor a d r a ~ ~ a~mlysis, cc most teaiirs just starting out wit11 OEE d o not need that level of detail. For llmt reason, this bonk follows n sirr~plcr ;~ppm;tch,~ ~ s eby r l Arno Koch of illom Co~~s~tlt:irrcy in his OEE 7bolkit softure, wl~ichcoillpares aetlrd output to the potcl~ti;dotllpilt if tile III? cI m' e were performing at its top speed.

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PUBLISHER'S MESSAGE

This book is especially lielpful when used with the O E E Toolkit sofhvare packagc (Productivity, 19993, \vliicli was developed by Arno Kocli of Bloni Consultancy to meet liis clients' need for a simple and flexible approach to O E E tracking. Tlie O E E Toolkit is an easy-to-use application for capturing OEE data and creating a wide range of reports from it. Tlie nianrial that comes with tlie software teaches a people-centered approach to OEE measurement and reporting ,

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I lie overall eqtiipinent effectiveness measure is simple and universal. It is used to measure and i~iiproveequipment conditions in companies all over tlie world. We hope this book will tell you wliat you need to know to rnake your participation and use of OEE active and personally rewarding.

Acknowledgments The development of OEE for Operators has been a team effort, and we greatly appreciate tlie eoritribution of everyone involved. The book was motivated by tlie approach to OEE developed by Arno Kocli of Blo~riConsulta~icvand further s~ipporteclby Itis OEE 7bolkit softwre package. content aclvisors included Jolin Jacinto of Amtes and Bob Strout of Lemforder Co., as well as Productivity consultant Jolin Monaco and ?'PA4 Report editor in chief Barry Sliulak. Lorraine h4illard of Productivity managed tlie prepress production and nianufacturing, with editorial ;~ssistancefrom Pauline Sullivan. Graphic illustrations were created by Guy Roster and Lee Smith, with cartoon illuslrations by Guy 130ster ;ind I-lannali Uonner. Cover composition was by Mark Weinstein of Produciivity, wit11 cover ill~~slration by Gary Ragaglia of Tlie Vision Group. Page composition was done by William 1-1. Brunson Typography Services.

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PUBLISHER'S MESSAGE

Finally, the Productivih staff wishes to acknowledge the good work of the many people who are in the process of implementing Total Productive Maintenance and using OEE in their own organizations. We welcome your feedback about this book, as well as input about 1 1 0 ~ we can continue to serve your iruprovement efforts. Steven Ott President Karen Jones Productivity Developnzent Team

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The Purpose of This Book Key

Po,n,

OEE for Operators was written to give you the infonrlution you need fo participate in using the overall equipment efecti~wms(OEE) measure in your workplace. You are a valued member of your compay's team; your kno\vleclge, support, ancl participation are essential to the success of any major effort in your organization. T h e paragraph you have just read explains the author's purpose in writing this book. It also explains why your company may wish you to read tliis book. But why are you reading this book? This question is evcn more important. What you get out of this book largely depends on your purpose in reading it. You may be reading this book because your team leader or manager asked you to do so. O r you may be reading il because you think it will provide information that will help you in your work. By the time you finish Chapter 1, you will have a better idea OF how the information in this book can help you ancl your company measure equipment-related losses and plan how to improve equipment effectiveness.

BILXGROYUB

What This Book Is Based On This book is about an approach for measuring equipment-related losses that limit the effecti\~enessof manufacturing equipment. Many of the ~netliodsdiscussed here were originally developed at conipanies working with the Japan Institute of Plant Maintenance, a pioneer in the a p p r o d i known as Total Productive Msintenance, or I'PM. Since 1988, Productivity, Inc. has nladc information about TPM approaclies available in the United States through publications, events, training, and consulting. Today, top conlpanies around the world are implementing TPA4 to stistain their competitive edge.

G E T T I N G STARTED

Figure 1-1.Two Ways to Use This Book

O E E for Operators clraws on a wide variety of Productivity's book and training resources. Its aim is to present the main conccp~s and techniques of 'I'IJPI and overall equipment effectiveness in a simple, illustrated format that is easy to read and understancl. This book also co~iiplcrnentsthe O E E %ofkit sofhvare package as a way to build a shared ~tnclerstandingamong workteam mcmbcrs before they begin using OEE.

Two Ways to Use This Book There are at least hvo ways to use this book: I. As the reading inaterial for a learning group or stttdy group process within your company. 2. For learning on your own. Your cornpany may want to hold a series of learning group discussions based on this book. Managers may assign the book for background reacling when the company uses the O E E Toolkit sofhvare package. Or, you may read this book for inclividual learning without forn3al group discussion.

G E T T I N G STARTED

How to Get the Most Out of Your Reading Becoming Familiar with This Book as a Whole There are a few steps you can follow to make it easier to absorb h e information in this book. Take as much time as you need to become familiar with the material. First, get a "big picture" view of the book by doing the following: I. Scan the Contents (pages v tlirottgli 141)to see liow OEE [or Operators is arranged. nil.

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2. Read the rcst of this section for an oven,iew of the book's contents. 3. Flip through the book to get a feel for it5 style, flow, and design. Notice liow the cliaptcrs are structured and glance at the pictures.

Becoming Familiar with Each Chapter After you l ~ w ae sense of the structure of OEE for Operc~tors,prepare yourself to study o n e chapter a t a time. For each chapter, we suggest you foiiow these steps to get h e mosl out oFyour reading:

1 Read the "Cllapter Otervieic" on tlie first page to see where the chapter is going. new

to steps

2. Ylip through the chapter, looking at the way it is laid out. Notice tlie bold headings and the key points flagged in the margins. 3. Now read tlie chapter. How long this takes depends on nhat you already know about the content, and what you are trying to get out of your reading. Enhance your reading by doing tlie follotvitrg: Use the niargin assis15 lo help you follow tile flow of inforrnation If the book i s your own, use a liighligltter to mark key inforrnation and answers to your questions about the material. If the book is not yoiir own, take notes on a separate piece of paper. Ansner the " ' M e Five" questions in the text. These will lielp you absorb tlie infor~natio~~ by reflecting on how you migltt apply it at work.

4. Read tlie "Chapter Surnmar)." to confirm what you have learned. If you don't remember something in ihe suliimary, find that section in the chapter and review it.

5 . l'inally, read tlie "Rcflcctior~s"qwstions at the end of tile cl~apter. Think about tliese questions and write down your a n s u m . I+id an expcricnced person to ask if you find a topic conft~sirtg.

GETTING STARTED

Figure 1.2. Giving Your Brain a Framework for Learning

How a Reading Strategy Works

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aeonle tliink tliev siiould start with \Vhen rcadine a book. tlie first word and read straight tlirougli until tlie end. 'niis is not usually tlie best way to learn from a book. l'lie steps de~cribcrlon page sv are a strategy for making your reading easier, more fun, and more effective. 0

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Reading strategy is based on two simple points about the way people learn. 'The first point is thk: It is difficult for your bruin to absorb rlew infonilcrtio~lif it does not h a ~ va str~ictureto place it in. A?an analog);, imagine trying to build a house \vitlioul first putting up a framework. Like Bnilding a frame for a liouse, you can give your brain a framework for the new inforru;~tionin tlie book by getting an overview of the contents and then flipping tlirough the materials. Withi11 e:~clich;ipter, you repeat this process on a sniallcr scale by reading the overview, key points, and headings before reading the test. 'The seco~itlpoint about learning is this. It is (I lot easier to lean1 if you take in the infonncition one layer a t a time, instead of frying to ubsorh it all at once. It's like finishing the nails of a liouse: First you lay do\vii a coat of primer. \\'lien it's dry, you apply a coat of paint, and later 4 final finish coat.

GETTING STARTED

Using the Margin Assists

As you've noticed by now, this book uses small images callecl margirt assists to help you follow the iriforniation in each chapter. I here are six types of margin assists:

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Background Information

Sets the stage for what comes nest

Key Term

Defines important words

Key Point

I-liglllights irnporiant ideas to remember

Example

W p s you understand the key points

New Tool

Helps you record data or apply learning

How-to Steps Indicates the sequence for improvement action

Overview of the Contents Getting Started (pages xv-xx) This is the section you're reading now. It esplai~isthe purpose of OEE for Operators and how it was written. T h e n it shares tips for getting the most out of your reading. Finally, it presents this overview of each chapter.

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GETTING

STARTED

Chapter 1.About TPM and OEE (pages 1-8) Chapter 1 introduces and defines 'Total I'roductite i\ilaintenance and overall equipmen1 effecti\seness. It explains reasons ivhv O E E is an important measure to track and describes the role of the shopfloor teani in collecting and using OEE clata. Chapter 2. Understanding Equipment-Related Losses (pages 9-23) Chapter Z describcs the three elements of OEE and links them to the main types of losses that lower equipment effectiveness. Chapter 3. Measuring OEE (pages 25-38) Chapter 3 offers guidance in measuring overall equipnient effectiveness, incl~rdingcollecting and processing data arid using the resulting information on the shop floor. It tells about defining what data to lucasure for the OEE calculation, doing the calculation, and storing the data so you can report the information in cliffcrent ways. Chapter 4. Improving OEE (pages 39-56) Chapter 4 covers essential approaches for improving overall equipment effectiveness. 'Topics include 5 Why analysis, the a u t o ~ ~ o ~ n maintenance ous and focused improvement pillars of TPR4, specific approaclies for setup and defect losses, and the advanced P-M analysis approach for chronic problems. Chapter 5. Reflections and Conclusions (pages 57-63) Chapter 5 presents reflections on and concl~isionsto this book. It also describes opportunities and specific resources for further learning about OEE, TPh.1, atid related tecliniq~ies.

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CHAPTER 1

What Is TPM? Overall ecjuipment effectiveness (OEE) is a key measurement in the in~provementapproach called Total Productive biaintenance (TPM). Before you begin learning about OEE, it is useful to understand a little bit about TPM.

TPM is a companywide approach for improving the effectiveness Key Point

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arzd longevity of machines. It is key to lean manufactitring because it attacks niaior wastes in operations. Developed originally to hclp a supplier meet the stringent recjuirements of the Toyota Production System, TPM is used today in companies around the world to improve the capability of their equipment.

TPhiJ has u number of waste-reduction goals, including equipment restoration and muintencrnce of standurd operating conditions. TPM methods also improse equipment systerns, operating procedures, und nzainterzance and design processes to asoid fiture problems. The main strategies used in TPM are often referred to as "pillars" that support the smooth operation of the plant. Figure 1-1 summarizes the activities in eight basic pillars of TPM. The overall equipment cffectiveness measure is important to many of the TPM pillars, but is probably most important to tlie first four pillars in the figure. This is because these pillars can directly influence O E E througli daily operations, maintenance, or improvenient activities.

ABOUT T P M A N D O E E

Activities

htonorno~~s maintenance

Operator invol\w~rentin regular cleaning, inspeclion, lulxication, and learning about equipment to mainlain basic conditions and spot early signs of trouble.

Qu;tlity maintenance

Aclitities to manage product quditl; by nraintaining optirnal operating cortditions. hlethotl~Lo h r t e n the lead Lime for getting nen cquipmenl o~llinc and making tlcfect-frec l)rotlucts. Safe9 training; integration of safey checks, visual controls, and mistake-proofing devices in daily work.

ii planned

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Figure 1-1.Basic Pillars of TPM

program for cleveloping crnployce skills and kno\\*ledgeto srtpport TPh4 inrplen~enla t'ion.

CHAPTER 1

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What Is OEE and Why Is It Important? Mmufacturing companies are in business to make money, and they make money by adding value to materials to make products the customers want. Most companies use rnacliines to acid valtic to tile prodrtcts. To add value effectively, it is important to rtm the machines ll effectively, with as little waste as possible. O ~ ~ e r aequipment effectiveltess is a nreasurerr~entused in TPM to indicate Itow effectively ~nacltinesare running. What do we mean by overall equipmenl effecti~~encss? ililany people are familiar witli the idea of "efficiency," tvliich ~ ~ s u a l l y reflects the cjuantity of parts a inachine or a person can prod~ice in a cerlain time. OEIS is rlifferent from efficiency in several ways.

Quantity Over Time Is Only Part of OEE

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Key Term

A machine's overall effectiveness inclucles more than h e quantity of parts i t can produce in a shift. When Jve measure overall equipment effectiveness, we acconnt for efficiency as oilc factor: krfomicriw?:a co~nparisonof the actuai outpttl with what llle inachine should be producing in the same time. In addition to performance, however, OEE inclt~dest\vo other factors:

Key Terms

i\,.ailahility: a comparison of the potential operating time and the time in which the machine is actually making products. Qualit).: a coinparimn of the number of products made and the nurnber of protllicts that meet the customer's spccificatioiis.

Key Poinr

When you nrultiply perfortnance, a~,cdability,and qualify, you get the overall equipment effectiveness, which is expressed us ct percentcige. OEE gives a complete picture of the machine's "health"riot jusl how fast it can niake parts, but how ~ u u c hthe potential output was limited due to lost availability or poor quality (see Figure 1-2). In Chapter 2 we will look more closely at these Lhree elements and lio\v they work together.

A B O U T TPM A N D O E E

Effectiveness Focuses on the Equipment, Not the Person

K ~ PI o i n t

Unlike s o ~ n euses of tlie efficiency measure, OEE monitors the machine or process that adds the value, not tlie operator's productivity. tV11er1we nmisure OEE, we look cit floiv well the equipment or process is working.

The Purpose of Measurement Is Improvement

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Measuring OEE is not an approach for criticizing people. It is strictly about improving the equipment or process. Used cis a17 impartial daily sttapshot of equipment conditions, OEE prornotes openness in information sharing crnd c~ no-hlarne cipproach in licindlirzg eqni/1rner7t-reluted issues. These key differences Iiighlight tlie importance of O E E as a balanced measure that I~elpssupport improvement and profitability.

TAKE FIVE Take five minutes t o think about these questions and t o write down your answers: Does your company currently measure each machine's efficiency? Its available running time? Its quality rate?

CHAPTER 1

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Rgure 1.3. Collecting Data and Turning it into Information

The Role of the Shopfloor Team in Using OEE This hook is written for sou, the sfiofifloor einiiloyee, because vou haw a big stake in the lzecrfth o/tlt; production kpipinent. operators, you manage the ecluipment that adds value to the procluci. When the ni;tchines break down, run too slowly, or produce defects, you have to \vork longer ancl harder to rnake t ~ for p tlie problems. 'Tlie pressure these problems creates is a good i~icentive to measure diem ancl start improving them. What$ more, your daily work ivit11 the machines puts you in the best position to inonitor their probleins. You know how long a ~iiacliine is shut down for setup, or w l ~ e minor ~i stoppages get in tlie way of Iiigh-speed operation, or when you have to run slower to avoid defects. In many cases, yokt already track the data that will be used to calculate the overall equipment effectiveness. Sharing in/orination on the plant floor through gruphs and discussion is the heort of TPiV (see Figure I-?). '['lie OEE information isn't rtseful when it is locked away in an office. 'The best approach for applying OEE gives operators a leading role in gathering daily data, coriverts the data into useful inforniation, and applies the information in the workplace to support improvement.

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A B O U T TPM A N 0 O E E

* Overdl equipment cffcctivcncss (OEE) is a key mcasurcment in h e irnprovcmcnt approach called Total Productive Maintenance (TPM).

TPM is a companywide approach for improving tlie effectivcliess and longevity of niacliincs.

* 'TPM has a number of waste-reduction goals, including cquipment restoration arid maintenance of standard operating conditions. 'TPM rnclliods also irnprove equipment systcms, operating proccdt~rcs,and maintenance ancl design processes re to avoid f ~ ~ t uproblc~m. Overall cquiprncnt effectiveness is a rne:~surernent used in TPM to ilidicate how effectively niachincs are running. Overall equipment effectiveness is not the same as cfficiency, wliich usually means liow many parts a macliinc or a person wap. l can produce in a certain time. O E E is different in s e ~ ~ e m Quuntity oiw tirile is only one port of OEE. A macliine's overall effectiveness inclutlcs more than the quantity of parts it can protluce in a shift. OEE inelucles also hvo other efficiency as one factor-perforttiatice-but factors-avnilabii and quality. Wlierr you intiltiply performance, availability, and qttality, you get the overall cquiptnent effectiveness, wliicli is cxpresscd as a percentage. Effcctitmess foctrses on the ecpiprrrent or process, riot tlie person. When we mcasure OEl:, we pay attention to how well tlie cq~~ipnient or process is perfonnirig, not tlic operator's productivity. Tile purpose of rneosurement is irrtprovemcnt. Used as an impartial dally snapshot of tlie cquipmetit, OEE promotes openness in infornialio~isl~ariiigand a no-blame approach in handling ccpipment-related isstlcs.

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O E E FOR O P E R A T O R S

* T h i s book 1s written for you, [lie shopfloor employee, because you have a big stake i n tlie liealtlt of tlie production equipment. What's more, your daily work with the macliincs puts you in thc besl position to monitor lheir problems.

* Sharing information on the plant floor tlirougli graplis and discussion is tlie heart of 'TPM

REFLECTIONS Now that you have completed this chapter, take five minutes to think about these questions and to write down your answers: What did you learn from reading this chapter that stands out as particularly useful or interesting?

* Do you have any questions about the topics presented in this chapter? If so, what are they?

CHAPTER 2

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Figure 2-1.Ideal and Actual Effectiveness

Losses Reduce Overall Equipment Effectiveness What makes machines less effective than they could be? Tlie ideal, totally effective machine could run all the time (or whenever needed). It could maintain its maximum or standard speed all the time. It \VOLII~never rliake defective products. But most tiiachincs aren't ideal. They cannot run continuously. They cannot maintain maxitnum speed withoi~tproblems. And they make defects.

m e 7 ipim

These problem are faniiliar forms of wask-they don't add value to the products. They reducc a machine's effectiveness, as measured by the OEE. The conditions that cause these machine probferns are called equipnlent-related losses. Uilderstandirig the different types of equipment-related losses will give you a framework for applying O E E and participating in improvement activities lo reduce the losses.

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U h D E R S T A l . O I Y G E Q L I P h. lE N T R E L A T-E D L O S S E S

T h e equipment-related losses that are important for O E E are linked to the three basic elements inertsured in OEE: availability, performance, and quality. Traditional TPM approaches track "Six Major Losscs": Quality: hailability Perforrnrince: Downtime losses Speed losses Defect losses E'1%'1 u m Minor stoppages * Scrap and rework Selup tinic * Reduced operaling speed Starlnp loss

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Altho~tglisome companies link i~iclivicluallosses to different O E E categories, or add otlier losses that are especially significant for their operations, this basic framework is a t~sefulstarting point for many companies. Figcue 2-2 on tlie nest page gives a visual image of tlie 1 1 9 in which these losses reduce the overall equipment effecti\~enessof a machine.

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TAKE F I V E Take five minutes to think about this question and t o write down your answer: What are some of the situations that keep your machines from running at an ideal level of effectiveness?

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CHAPTER 2

OEE = B/A x D/C x F/E x 100 ~vailhbility

~erfdrmance

Quality

Figure 2-2. The OEE Elements and the Equipment-Related Losses

Visualizing OEE and the Losses

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Figure 2-2 makes it easy to see itow OEE is derivcd from the three elerrients, expressed as fractions. Each pair of bars stands for one of the fractioris-availabiliQ (BIA), performance (DIC), and cpality (FIE). 'The fractions arc often multiplied by 100 to trrrn them into percentages or rates.

Availability Bars A a d l3 represent availability. Unsclieduled time shortens the total operating time,* leaving net operating time (A). But the "Companies eouiit l l i i s t i ~ r i eill different ways, b u t for I l l i s discusniori, we sd,tract t l ~ e r e periods from tllc t u t d upcrating lime.

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U N U E H S T A N D i h G E Q U I P h l E h T - R E L A T E D LOSSES

~nacltineis frequently down during some of that time, usually due to breakdo\vns and setup. Subtracting that downtinie leaves the running time (B) in which the machine is making product.

Elanpie

Performance Bars C and D represent perform;tnce. During the running time, tlie machine co~tldproduce a target ouipit quantity (C) if it ran at its clesig~ledspeed the whole time. But losses such as minor stoppages arid reduced operating speed lower tlic actual output (D). LTxur~tple: tnanole

acluul orrfprrt -- 15,000 pmts = .60 prfinrrurrce (x 100 = 60%) target otrfpuf 20,000 purls

Quality Bars E and 1' represent quality. Of t l x actual output (E), most of the product is good output (F). But usually some output falls short of the specified quality and must be scrapped or reworked. Scrap is often produced during machine startup as well, lowering the yield from the inaterials. Exria~ple:

H

B

point ~

good outp~tt 11,760 parts -= ."18 qualify (x I00 = 98%) ucl~rrrloutput 12,000 parts

Figure 2-2 shows how losses to availabilih, perfont~unce,and quality corrzpourzd to reduce the amount ofgood output CI n~uchine cun produce during a shift. You can improve quality to raise tlie quantity of good output a little bit-but the total quantity won't rise draniatically unless you also improve both performance and availability. The fortnula at tlie bottoni of Figrtre 2-2 shows how lo ~nultiply the three elements to gct the OEE.

The rest of this chapter will look more closely a1 the losses associated with these elcmcnts.

1

CHAPTER 2

I Figure 2.3. Downtime Losses-Failures and Setup

Availability: Downtime Losses Failures

Avuifubility is reduced by equipzrrent fuilures, tvliicli are a common occurrence in many plants. RiIacliines used for prorluction generally have lots of moving parks and vario~tssubsyste~iisin wliicli hiings can go wrong. Il'lien they do, the niacliine breaks downand stays down ~ ~ n trepairs il are completed. Key P o i a t

Many oftlie causes of ri~uclrinefi~iluregive wurrting signs before the rriuclri~~e uctuully Irreuks. In Cliapter 4 1ve will look at liow autonomous maintenance activities can help spot early trouble signs in time to prevent major breakdowns. Setup Time

Key F o l n l

rh~uilubilityis also reduced by the time it tulies to set up the tnuchine for u different product. hi addition to cliarigirig tlic valueadding parts, a cliangcover requires some preparation or makeready. It may ~nvolvecleaning and making adjuskmcnts to tile machine to get stable quality in the nest product. Too oftcn, it also in~olvesrunning around to find tools, parts, or people. \lJe will considcr an approach Tor retlucing sct~tptime in Cliapter 4.

I

Figure 2-4. Downtime Losses-Cutting Tool Loss and Startup Loss

Other Losses to Availability Failures and setup losses were the original losses counted as clow~itimethat recluces availability. Some cornpanies also track other losses as downtime, depending 011d i a t losses they are trying to improve. Cutting tool loss, startup loss, and time not schednled for production are three other losses tracked as downtime at some plants. Cutting Tool Loss Key P o i n t

Rreukuge of cutting tools during production cuuses unpluz~ned downtinze while the tool is replaced. Altliougli this is teclinically a subset of failure ancl repair losscs, some companies track it separately because of the potential for injury ancl product defects, as well as the cost of tool replacement. Planned maintenance and autonoriioi~smainienance activities help reduce these losses. Startup Loss

K*Y point

Startup loss is traditionally incl~~ded as a defect loss, since its essenie is the prod~tctionof defective products during startup. I-lowever, sturk~ploss involves lost time until good pod~rction~cun be stubilized, so it is logical to st~btractit From available time as well. 15

I

CHAPTER 2

Figure 2.5. Downtime Losses-Unscheduied Time

Time Not Scheduled for Production

In some con~panies,when rnacl1ines are stopped for meetings, preventive maintenance, or breaks, the time is considered "not schecluled" and is not counted in the availability rate (see Figure 2-5). Other co~npaniesrecognize that even necessary activities like tliesc reduce the available prodnction time. They may clccide to consider time "not scheduled" as a downtime loss that lowers the availabiliky rate. Key Point

Counting tmscheduled time as (I loss cut1 erzcotrrage creative ideas for reducing the loss-without eliminnting the uctivify. For esample, after measuring the produckion time lost from scheduled breaks, employees at one company developed a plan to alternate their breaks and briefly cover each other's stations.

U N D E R S T A N D I N G EQUIPMENT.RELATE0 L O S S E S

Likewise, some companies count offline time for preveniive maintenance as do\vntirrie. Again, the point is to rcduce the tirue loss, not to eliminate the activity.

TAKE F I V E Take five minutes t o think about these questions and to write down your answers: How much time is lost each month due to failures and repairs in your area? How much time is spent each month on setup and make.ready in your area? Would you count other time losses for OEE purposes? Why or why not?

CHAPTER 2

Performance: Speed Losses Reduced Operating Speed Machines often nrn at speeds slo~verthan they were designed to nm. One reason for slower operation is unstable product quality at the designed speed. In other cases, people don't realize h a t the equipment is designed to run laster. We tvill look in Cliaptcr 3 at how to determine speed for the OEE ealculalion.

Minor Stoppages Minor stoppages are events that interrupt the production flow without actually making the rnaclrine fail. 'I'ltey often occur oil autoruated lines, for example witen product components snag on the conveyor (see Figure 2-6). Minor stoppages can make it impossible to run automated equipment without someone to monitor it. Tllese stoppages may seem like petp annoyances, but they add up to big losses a t many {dank.

U N D E R S T A N D I N G E Q U I P M E N T - R E L A T E D LOSSES

h h o r stoppages last only a few seconds, so we don't try to log the time lost. Instead. we inclt~detlieni in r~erformancelosses that reduce the product output. We will look at approaches for reclucing speed losses in Chapter 4.

TAKE FIVE Take five minutes to think about these questions and to write down your answers: Do you know the designed speed of the machines in your area? Do minor stoppages happen in your area? What causes them?

CHAPTER 2

Figure 2-7. Defect Losses: Scrap, Rework, and Startup Loss

Quality: Defect Losses Scrap and Rework

I'roducts that do not meet customer specifications are a familiar loss. Clearly, scrap that cannot be reused is a waste of m;~terials. Even when prodt~ctscan be reworked, the effort spent to process them hvice is a waste. Startup Loss Key

Many machines take time to reach the right operatiltg conditions at startup. f n the n~eatztime,they nay turn out defictive products while operators test for stable output. Some companies simply include this startup loss in scrap and rework; others single it out as a specific loss to track*

"r\s nreiiticrncd in the section or1 dow~lirtieiosscs, same cortipnier also sir& out the slnrlup period bcforc tlic first good prc~rliictns ;I special vpe of do\vntime to h c k .

UNDERSTANDING EQUIPMENT-RELATED LOSSES

Quality ~xoblemshappen when the optin~umconditions do not exist at the moment \dien a person or machine works on the product. In Chapter 4 we will look at a meihocl for preventing defects by checking and controlling the necessary conditions.

TAKE FIVE Take five minutes t o think about these questions and to write down your answers: What is the defect rate for machines in your area? Do you think this can be reduced? Are startup losses a significant problem in your area?

O E E FOR OPERATORS

The ideal, totally effective machine would run all the time (or n.henever needed), at maximum or standard speed, with no quality problems. But most machines can't meet tlicse ideal conditions. They can't run continuo~~sly or at maximum speed; they experience minor stoppages, and tlicy make clefective parts. Tl~eseproblen~sreduce a inachine's effectiveness, as nieasured by the OEE. Tl'lic conditions that cause these probleins are called eqrtipmerit-related losses. Linked to the three basic elemcnls of OEE, they include the traditional "Six Major Losses": AvailabiIity: 1'crfonn:rnce: Q.;ility: Downtime losses Spceci losses Defect losses Failures Minor stoppages Scrap and icwork Setup time Reduced operatir~gspeed St;~rtuploss

.

itltliot~ghsome companies link individual losses to different O E E categories, or add otlier losses illat are especially significant for their operations, this basic framework is a i~scful starting point. O E E is derived from the tliree elements, esprcssccl as fractioris. 'i'l~efractions arc often multiplied by 100 to turn tlicni into percentages or rates. Losses to tlmc tliree elements rcdtice tltc arriount of good output a machine can produce during a shift. Downtime losses arfcct availability. Eailtires and setup time are comnion losses tracked. So~iiecompanies ;dso track otlier losscs as downtime, depending on what tlicy arc trying to intprove. Cutting tool lo~s, startup loss, and time not scheduled for production are three other losses son~etiniestracked as downtime. Speed losses affect performance. h h o r stoppages and operation at reduced spced are often measured as speed losses.

r

UNDERSTANDING EQUIPMENT-RELATED LOSSES

* Defect losses affcct quality. They include scrap and rework whcn products do not meet customer specific. I'Ions. Also, many macllines turn out dclcctive products during startup while operators test for stable oulpttt. Some conipa. nics i n c l ~ ~ dthis e loss in scrap and rc\vork; others single it out as a specific loss to track.

REFLECTIONS Now that you have completed this chapter, take five minutes to think about these questions and to write down your answers: What did you learn from reading this chapter that stands out as particularly useful or interesting? Do you have any questions about the topics presented in this chapter? If so, what are they?

CHAPTER 3

Point

A~Icasuringoverall equipment effccti\~enessis an important way to monitor which losses are reducing the effecti\~enessof your macliines. By tracking OEE 077 a regular basis, you car7 spot patterns and influences that cause problenrs for production equipment. Furthennore, niecrsuring OEE allows you to see the results of your efforts to help tltc rnaclrines nm better. This chapter offers guidance in measuring overall equipment effectiveness, including collecting and processing OEE d a b arid reporting OEE results.

Closing the Feedback Loop The process of measuring and applying OEE data should involve the people who use the machines. As operators, you are more familiar than otlier people with the equipment you operate, and you have a slake in helping it run well. Therefore it's logical for you to take part in collectirig tlie data for calculating OEIS. Key point

just as irrzportant as being involved in clata collectiotl is receiving feedback on OEE results. An O f X chart cannot promote improvement if it doesn't get back to the shop floor. OEE is living information for improving equipment effective~iess.It shoulcl not be buried away in an office.

Collecting OEE Data Defining What to Measure mey

poio,

Before you can begin appl)>ingOEE, you need to decide what nrachine and prod~~ct datu you will rneasure for the calcufatiot~. V i e Basic itenis you will measure are the losses that reduce availability, perforninncc, and quality. Tliese will vary from plant to piant, b ~ the ~ tSix h4aior Losses described in Cliapter 2 give a good framework to start from. Downtime Losses

Key Po,ol

Do~vntimelosses (lost ai,c~ilclbility)crre rrwcrsured in units of tirnc (Figure $-1). They include failure and repair tirnc setup and adiustmenk timu other time losses tli;it reduce availabililp

I

I

MEASURING OEE

:ure 3-1.Failure and Setup Losses Are Measured as Time Losses

Failure and repair time i n c l ~ ~ d all c s of h e downtime until the rn:tclhe makes the nest good product. Some plants 1i1mpall breakdotvns into one category; other plants may create several categories to disti~tguishbet\veen different hpcs or causes of rnachinc failures. The main t l h g is to standardize yow approach so everyone can measure a failure event the same way. Setup and adiustmcnt tifne includes the time between the last good piece of procluct A and the first good piece of procluct B. Other time losses include startup losses-similar to setup time losses-and any nonsclted~~led time the team chooses to subtract from the available time.

TAKE FIVE

Take five minutes to think about these questions and to write down your answers: What types of information about your machine's operation do you currently track? What types of downtime losses do you think your work area would track for OEE?

CHAPTER 3

THE DESIGN GUY SAID THIS WOULD RUN 1,000 PIECES P E R MINUTE. BUT WE CAN ONLY RUN 827 MATTER WHAT

Output Reductions

Speed Losses

Hey poin,

Speed losses (lost perfonncince) are rneclsured in units of product output (see Figure 3-2). You probably already track your outpt~t quantity. For OEE, you look at the difference behveen the actual output and the potential output if the riiacliine consistently ran at the designed speed, or at the standard opti~nuntspeed for each procl~tct. Speed losses include minor stoppages as well as reclucecl operating speccl. Altlio~~gh minor stopp"ges are "events" like minibreakdowns, they often occur so frecluently that it is not practical to record the tin& lost during many frequent stoppages. For that reason, many companies monitor minor stoppages by tracking the output reduction they cause.

'lb comficlre the actual outbut rate (rnuchine s ~ ~ e ewill1 d ) the outbut

,,, ,,,,,

rate at ;he designed speed,'pu have to know & z tthe designed &zx! is. If tl~isspeed docs not appear in tiic macltine's docurnentakion, you will nked to sel :I stari~ard,such as the fastest known speed at wltich the machine can run (tliis may vary for different products).

MEASURING OEE

Percent

-

/

Defect Rate, Line C

Figure 33. Scrap and Startup Losses Are Measured as Defective Output Compared to Total Output

Defect Losses

Key volnt

Defect losses (lost quality) are ulso measured in units of product output. 'This time, you are looking at the difference behveen the total act~taloutput and the output that meets ccustomer specifications (sce Figure 3-3). Defect losses include products that can be reworked as well as outright scrap. i7irst-pass qualih is the goal.

Making Data Collection Simple The purpose of tracking OEE is not to rliakc estra paperwork for operators. Most likely yo11 arc alreztdy collecti~ig;I lot of the data req~~irecl for the O E E calculation. One ivell-clesigiled fonn cun nlake it easy to log the OEE data as i ~ ~ eusl l other dutct you need to register clurir~gdaily production.

CHAPTER 3

Elampis

Figure 3-4 (pages 31-32) shotvs a sample data collection form. Its creators used a simple approach for logging time losses by sliading the boxes on Side A to indicate where downtinie occurred. Performance and quality data go on Side B.

TAKE FIVE Take five minutes t o think about these questions and to write down your answers: Which type of loss most affects your production equipment? How would you change your current data collection forms to include OEE data?

MEASURING

OEE

Lure 3.4. Sampie Data Collection Sheet (Side A)

Source: A

m

Kach. Blom Consultancy. User's Guide for OEE Toolh~tsoftware IPmductivity, 19991

31

CHAPTER 3

:we 3-4(continued). Sample Data Collection Sheet (Side 6 ) SOUICB: Arna Koch. Blom Consultuncy. User's Guide lot OEE rootkit software (Productivity, 1999)

MEASURING OEE

Running time Net operating time

Actual output

I

Target output

I

Good output Actual output

Figure 55. The OEE Calculation and Its Elements

Processing OEE Data Afier you collect data for OEE, you need to process tlic data to turn it into useful information. This involves doing the calculation, and also storing your data in a way that allows you to clraw different types of idomtation from it.

The OEE Calculation OEE is calct~lateclby multiplying availability, perforniance, and qudity (~nultiplieclby 100 to give a percentage rate). OEE rote = i\wifubility x Perfarntanoe x Quulity x 100 Po'nt

Let's review the equations for tlte individual elcrnents of OEE. = A~~uiluhilih

Kunnirrg tirile Net ctperutirrg tirne

The running time is the net operating tirne minus the downtime losses you rlccide to measure. Perforn~c~rtce =

Actual output Torget ozrtput

For the OEE calculation, the target output is the quantity the machine woulcl produce if it operated at its designed speed during the running time (see Figure 3-5). Qt~atity= Good output Actuul output

CHAPTER 3

Storing OEE Data O E E is mos1 valuable when p o collect ~ ~ data and do the calculaLion on a regular basis. Tracking O E E at set intervals over time allows you to see patterns that give ciues for in~provement. riel

Pa~nt

It is irnportat~tto have a system in pluce to store your O E E data. Manual charting of the basic rates is a good place to start, but it limits the information you can pull out of the data. Sofhvare can be a helpftd tool for automating the calculation and storing the data for use in scvcral t ~ ~ p ofgrapl~s es (see Figure 3-6).

I

TAKE F I V E

Take five minutes to think about this question and to write down your answer: What kind of data storage system would you want to use for your OEE measurements?

MEASURING OEE

Source: Sample data entered in OEE ibolkit software application (Am0 Koch. Blom Consullancy: PIoducthify, 19991.

Reporting OEE Results Sharing O E E information is critical for reducing equipmentrelated losses. Operators-the people who are closest to the ccpipment-need to be aware of OEE results. lieporting OEE information on cliart~in the \vorkplace is a key to improving future results. T h e graph in Figure 3-6 s h o w a typical machine's O E E chart for one sliift. By tracking this data over time, vou can see tlie OEE trends for the machine, as shown in F'igur; 3-7.

,,, ,,,,,

The few pieces of data you collect to track OEE con give a lot of other information about the inuchine, unswering sttch questions as Arc we improving over How arc we utilizing tlie time? equipment? What are the biggest downWhat is our mean time time problems? behveen failures, failure rate arid frequency, and When did an incident occur? mean time to repair? 1-low was quality over the last month? Figures 3-8 and 3-9 show sample reports from O E E data.

CHAPTER 3

Source: Sample data entered in OEE Toolhi! software appilcation ( A m Koch. Blom Consultancy; Pioducfivity, 1999).

Figure 3-9.Utilization Chart SOUICB: Sample data entered in OEE Toomil software application $ A m Kocll. Blom Coosultancy; Pmd~ctivity.1999).

MEASURING OEE

* Tracking OEE helps you spot patterns and influences of equipment problenis 2nd allows you to see thc results of your iniprovcment efforts. 0

Tlic process of measuring and applying O E E data should involve tlie people who use tlie machines. Operators should also receive feedback on OEE results.

* Before you bcgin applying OEE, you need to decide what lo measure for tlie calculation. The basic i t e m you will measure are the losses that reduce availability, performance, and quality. Tbcse will vary from plant to plant, but tlie Six Major Losses provide a good starting Franietvork. Downtime losses (lost availability) are measured in units of time. They includc hilurc and repair time setup and adjustment time other time losses that reduce availability l

Speed losses (lost performance) are measured in units of product output. You will look at the difference behvcen the achial output and the potential output if tlie machine consistently mn at the designed spced or the st;~nclardoptimum speed for each product.

* Defect losses (lost quality) arc also nieatured in units of product output. Here you itre looking at Llic difference betwecn h e total actual output and thc output that meets cusiomcr spccificat~ons. The purpose of tracking OEE is not to 1ii;lke extra A \vcll-designed form can make it easy to log the OEE data as wcll as other data you rieed to register during daily production. A f t e r you collect data for OEE, you need to process the data to turn it into useful information. This involves cloing the calculation, and also storing your data in a way that allows you to draw diffcrcnt types of information from it.

O E E FOR O P E R A T O R S

OEE is calculated by n~ultiplyingavailability, performance, and quality (tnuitiplied by 100 to gct a percentage rate). OEE rate = rivuilability x Perfonnunce x Ql~ulilyx 100 = ri~~uilubility Perforn~ance=

Running tirile

Net operrrtitig tirne Actual output Target oufptrl

-

Q ~ r a l i h=

Good unlptrt Actual oritplrt

Tracking OEE at set intervals over time allows you to scc patterns that give clues for improvement.

* It is important to have a system in place to store your OEE data. Software can be helpful for autorriating the calculation and storing the data for use in reports. Reporting the results on charts in the workplace is a key to improving fut~ircresults. The few pieces of data you collect to track O E E can give a lot of other information about the machine.

REFLECTIONS

/

Now that you have completed this chapter, take five minutes to think about these questions and to write down your answers: What did you learn from reading this chapter that stands out as particularly useful or interesting? Do you have any questions about the topics presented in this chapter? If so, what are they?

I

CHAPTER 4

Figure 41. OEE Tells the Current State of the Equipment

W measure O E E to ~ilonitorthe condition of the cquipmentsimilar to what a nurse learns about your condition when he or she takes a temperature or listens io a heartbeat (see Figt~re ,. 4-1). By comparing yesterday's or last \veers result, we can see whether tlie condition has improved or become worse. As an operator, you play an important role in 'TPM because you are in the best position to monitor machine conditions during operation. Key Point

?'fie i~ointof usirlg the O E E meusure is to drive irnprovenient. When you first begin tracking OEE, the rate mag be very low. This is no1 totally bad, because it means there is a big opportunih to improve. It is much easier to improve a low OEE rate than a high one, since people tend to eliminate the obvious wastes and problems at tlie beginning. Standardization is the first step in improvement. 0 E E is a tool for standardizing the way you measure effectiveness. This standardized approach provides a baseline that helps you see where to focus improverneiit efforts.

,,,

Some improvement mag happen just from the awareness that develops when you start mcasuring OEE. Sustuined improvetnent, however, requires a dediccited approach, with rrlunugerrtent support. This cliapter explores several approaches that can help improve OEE.

iMPROVlNG OEE

Answer

2. Why did oil leak?-

---p

/

I

The O-ring was cut.

Figure 4.2. 5 Why Analysis

5 Why Analysis I-Iave you ever liad the esperience in \vl1ich someone fixed a machine problem, but the same problem happened again after a sliort time? In such cases. it often h~rnsout that people have been heating the syinp toms of the problem, but not dealing \\it11 its real, root cause. &ti we address the root cause, the same problem will keep returning. s

.

5 Why analysis is a useful tool that brings us closer to tlie root cause. As its name suggests, 5 Why analysis involves repeatedly asking "~vhy?"about the problein (it could he more or less than five times, depending on the situ;ition). This leads us to look beyond the inirnediate effect-sucti as a broken drive belt- to see the factors that might be causing tlie effect-st~cli as flaws on tlie pulley that make the belt wear out too soon. Figure 4-2 shows an esarnple of using 5 Why analysis. TAKE F I V E

Take five minutes to think about these questions and to write down your answers: Is there a typical situation in your workplace where people "fix the symptoms"? What do you think is the root cause, and what would you do about it?

CHAPTER 4

1

Autonomous Maintenance 1

.:,;:[

.. ....

, ~,, .-, ~ $

Key

Term

Autor~ornousrnairtiertunce refers to activities curried out by s/iopfkor terns in cooperation with muintenatlce staff to help stub i k e basic equipment conditions and sl~otproblents early. Autonomous maintenance is one of the pillars of TI'M It changes the old view that operators just run machines and maintenance people just fix them. Operators liave valuable knowledge and skill that can help keep equipment from breaking down. In autonomous maintenance, operators learn how to clean the equipment they use every clay, and how to inspect for trouble signs as they clean (see Figure 4-3). They may also learn basic lubrication routines, or at least how to check for adequate lubrication. ?'hey learn simple niethods to reduce contamination and keep the ecjuipmcnt cleaner. Ultimately, they learn more about the various operating systems of the equipnlent and may assist technicians with repairs.

KBY P ~ I " ~

Auiotlo~nousmaintenance activities arc like exercise and regular I~eulthcheckups for machines. Along with preventivc maintenance, they help raise O E E by lilaititaining proper operating conditions, and stabilize it by detecting abnormalities before they turn into losses.

IMPROVING OEE

Step 1. Conduct initial cleaning and inspection. Step 2. Eliminate sources of contamination and inaccessible

areas. Step 3. Develop and test provisional cleaning, inspection,

and lubrication standards. Step 4. Conduct general inspection training and develop

inspection procedures. Step 5. Conduct general inspections autonomously. Step 6. Apply standardization and visual management

throughout the workplace. Step 7. Conduct ongoing autonomous maintenance and

advanced improvement activities. Figure 4-4. Autonomous Maintenance Activities

,,,

?,,

Autonomous maintenance is. at its heart. a team-based activik. Through the steps ofautonornous maintenance, shopfloor employees work with maintenance technicians and engineers ton'clrd a 13y sharcotnnzort goal-more effective equipment (see Figure 4-4). ing what they know, they can catch many o f the problems that cause failures, defects, or accidents.

TAKE FIVE Take five minutes to think about these questions and to write down your answers: Who performs basic cleaning and maintenance on the equipment in your work area? Do you think autonomous maintenance activities would reduce equipment problems in your company? Why or why not?

CHAPTER 4

L

Figure 4.5 (a). Stabilizing with Autonomous Maintenance

Focused Equipment and Process Improvement K e y Tern

Focused equipment clnd process ilnproventent is the ?'l'h/I pillur tliat deals most directly with irr~provingequipment-related losses. If autonomous maintenance and preventive maintenance activities are like esereise and health checkups, focused improvcnient is like an intcnse workout tailored to develop strength in specific m ~ ~ s cgroups. le Autonomo~~s maintenance a ~ i dplanned maintcnance inlprove O E E Lo a certain level, then help niaintain basic operating conditions to stabilize OEE. To raise OEE beyond this stabilized level, companies apply focirsed improvement (see tlie left and right sides of Figure 4-5). In corttrcrst to the onrroine activities of autonomous maintenance w and planned maintenance, foc~lsedimproventent involses targeted ~rojectsto reduce specific losses. These projects are usuallv carried out by cross-functional teams that include people with various skills or resources an improvement plan might require. Depending on the target, a focused i~nprovementteam may include maintenance technicians, engineers, equipment clesigners, operators, supcnkors, and managers. w

Key P o i n t

I

I

K e y Po,n,

IMPROVING OEE

It's u good icleu for companies to attuin a basic "fit~~ess" level with U U ~ O ~ I ~ I U O~nuinte~~unce US cind pkunned tnaintenance before launching focused intprovenlertt projects to address specific weaknesses. One reason is to eliminate routine problems (sporadic losses) so yo11 liave a clear view of clifficult or more significant proble~iis(chronic losses). Another reason is to avoid wing a more expensive and time-consuming foc~~sed improvement approach for problems that could be addressed tlirough less expensive autononious maintenance or planned maintenance. Focused improvement teams use a range of approaches to cut equipment-relate losses. They may use 5 Why analysis as a starting point, but there are also approaclies that addrcss specific types of losses, such as setup losses and scrap. We will review approaches that deal directly with shortening cliartgeover time arid reducing losses froni product defects. Finally, we will look at P-bl analysis, an advanced version of root cause analysis that is used in focused improvement and quality maintenance.

I

CHAPTER 4

Before SMEO Internaland external setup

Convert internal

internal and

Streamline all aspects of setup

Figure 45.The Three Stages of SMED

Quick Changeover Setup and adjustment time is an iniproveiiient target for OEE, since it reduces tlic time in which the machine is available to make products. Sliigeo Sliingo, who helped develop key aspects OF the Toyota Production System, invented a changeover irnprovement system called single-minute cscliange of die," or SMED. This system gives a threestage approacli for shortening setup (see Figure 4-6).

Stage 1:Separate Internal and External Setup In developing S h E D , Sliingo analyzed changeover operations to detertiline why they took so long. He recognized that changeover activities co~tlclbe divided inlo two types: ftltcmrtl setup: setup operations that can be done only with the cqt~ipnientstopped

* Externul setup: setup operations that can be done while the iiiacliine is working.

The problem a t most contpanies is that internal c~ndexternal setup operations ure rnisecl together. This means that things that could be done while the machine is running are not done until the machine is stopped.

'Nirned lor ihc goal of cnri~pletir~g cl~ai~getrver witlii~~ ;I single-digit ilwilber or lciver. utcs-9 iiii~~tilcr 46

of

niio-

I

IMPROVING OEE

Stage I of Shingo's SMED system i r l ~ ~ o i sorting ~ e s out the external setup oparations so they can be done before the iitacl~ineis stopped. This alone can reduce s e t u f ~time bv 30 to 50 /~erceitt.Typical stage 1 activities include 'liansporting tools and parts to the macliine in advance Confirming that escl~a~lgeable parts are functional before the cl~angeoverbegins

Stage 2: Convert Internal Setup to External Setup T h e next step in the SkIED system is to look again a t activities clone with the mnchine stopped ancl find ways to d o them while the n i a c h i ~ t cis still active. Typical stage 2 improvements inclilde Preparing operating contliiions in adranee, sttch as heating a die mold with a preheater instead of using trial shots of hot material Standardizing functions sue11 as die height to elinhate tile need for adjustments Using devices tlmt autonmticallp position the parts witliout suremcn t

II~GI-

Stage 3: Streamline All Aspects of Setup This stage attacks remaining setup time, and includcs these approaches to shorteii internal setup: Using parallcl operations (two or more people working together) Using quick-release cl;t~npsinstcad of nuts and bolls Using numerical settings to eliminate trial-and-error adjustments

TAKE FIVE Take five minutes t o think about t h e s e questions and t o write down your answers: How long does a typical changeover take in your work area? Can you list the changeover steps that couid be performed while the machine is still running? Who would you want to have on a setup improvement team, and why?

I

CHAPTER 4

Source inspection + 100 percent inspection + Prompt feedback and action + Poka-yoke systems

I Figure 4-7. The ZQC System

ZQC (Mistake-Proofing) The quality rate is an element of OEE. When the equipment that sliould add value to a product makes a defect instead, it wastes valuable materials and energy-and it can Iittrt tlie company's reputation if tile defective item reaches a customer. Therefore, quality is an important clement of a machine's effectiveness. Many companies think that they are addressing qualiky issues through inspection that catches defects before they leave the factory. However, inspection after {~rocessingcloes not elimincrte defects, a r ~ ddoesn't necessc~rifycatch tflern all, either. Quality cannot be "inspected in." It t i i ~ s be t Built into the process.

BI

erm

~ e Py o i n t

Shigeo Shingo carefully analyzed the causes of defects in manufach~ringplants and found that random errors were often the most difficult causes to control. To prevent hese errors, he developed a mistake-proofing system known as Zero Quality Control (ZQC, or "quality control for zero defects"). ZQC prevents defects by ccltching errors cmd other nonstanclctrd conditions before they actuc~llyt t m info defects. It ensures zero defects by inspecting for proper processing conditions, for 100 percent of the work, ideally jt~stbefore an operation is performed. If an error is discovered, the process shuts down and gives itmnediate feedback with lights, warning sounds, and so on. TIie basic elements of a Z Q C system are summarizecl in Figure 4-5.

I

IMPROVING OEE

press

8

correct

limit switch (poka-yoke) detects correct

incorrect

I Figure 4-8. A Poka-Yoke Example

Poka-Yoke Systems

Because people can rnake mistakes even in inspection, nristakeproofing relies on sensing nzechanisms culled poka-yoke system, which check conditions autonzatically and signul when problems occur. I'oka-yoke devices include electronic sensors such as limit switches and ~~hotoclectric eyes, as well as passive devices sucli as positioning pins that prevent l~ackwardinsertion of a workpiece. Figure 4-8 sho\tss an esantple of a limit switch used as a poka-yoke system to prevent processing wlien the work is placed incorrectly. Poka-Yokesystems may use counters to make sure an operation is repeated the correct number of times The key to effective mistake-proofing is determining when cntd ~ I t c r edefect-causing conditions arise and then figuring out how to detect or prevent these conditions, every time. Sliopfloor people have important knolt4edgc and ideas to share for developing and implementing poka-yoke systerns that cheek every item and give iniiiiecliate feedback on problerns.

TAKE F I V E

Take five minutes to think about these questions and to write down your answers: What types of actions or conditions can cause defects in your process? At what point could you detect such an action or condition? Who would you want on a mistake-proofing team for your process, and why?

CHAPTER 4

Figure 4.9. Chronic Problems Require an Advanced Approach

P-M Analysis You may have experienced situations when you have to makc repeated repnirs ind adjustments on a recurring problem 4 1 ure 4-9). When a problem conies back, it is usually because the sitrtatiori is not as simple as we originally thought it was. Our 5 Why analysis may have followecl one factor to a clecpcr cause, but real life is coniplex and interrelated-several factors often work iogether to create a particular problem. P-Ad analysis is u tool for systen~crticallyuncoiwing und testing all the possible factors that could contribute to a cl~ronicproblem such as defects or failure. The "P" in P-it1 analysis staiicls for "phenomenon"-the abnornial event we want io conlrol. It also stands for "pliysical"-the perspective we take in viewing the plienomenon. "bI" refers to "mechanism" and to tlie "4Ms"-a franiework of cai~salfactors to examine (Macliine, MenAb'ornen [operator actions], Material, and IvIethod). P-kl analysis is often spelled with a hyphen to clistinguisli it front abbre\iatioils for preventive or plannecl maintenance. Ksy Paint

The esscncc of P-&I Analysis is to look systetnutically at n f e y detail phen~tnetzu,underlying condition, or causal @or is missed. Although product clefecis and equipment failures are tlie losses most often addressed, P-b1 analysis can be applied to any loss that i~ivolvesan equipment abnormality.

SO 110 physical

IMPROVING OEE

P-kS analysis involves physically analyzing chronic losses according to the principles and natural laws that govern Lliem. T h e basic stepsof P-h/I analysis are . . . .. .. .

,

now.to steor

1. Physiccilly analyzing chronic probierr~saccording to the ir~acltinc~s operciting principles. This means understanding-in precise physical term-what happens \&en a n~achinetnalfunctions. T ' o do this, the team riwst first understand the physical standard for normal operation.

2. Defining the essential or constituent corlclitions underiyiilg the abnoni~al pltmomenc~.This means understanding at the physical level dial conditions exist when the macliine doesn't work right. Examples include the position of the work or the temperature ofa cult~ngtool. 3. Iderttifiirlg ali factors thtrt contribute to the phenort~cntrin terms of the 'fM fictrnovork. 'This means examining the problem from several viewpoints to uncover factors the tcam might otlicnvise overlook. After going through these steps, the team surveys for the presence of the factors, then tests inqxoventerit actions. I~igures4-10 and 4-1 1 on the follo~vingpages are P-bI analysis tables. Figure 3-10 shotvs how infor~nationis developed at each step. Figure 4-1 1 d~ow 1io1v the team checks for factors and tests its improvements.

P-144 unulysis is considered an advanced tool becouse this level of ney volnt

"detective work" requires rnore time, resources, and expertise than

5 Why analysis. For these reasons, focused improvement teams may save P-M analysis for complex or costly problems.

TAKE F I V E Take five minutes t o think about these questions and to write down your answers: Think of a familiar situation where a machine problem recurs. What do people usually do about it? Can it be resolved with 5 Why analysis, or does it need more analysis?

CHAPTER 4

cure 4-10. P.M

Analysis Tablo

52

I M P R O V I N G OEE

:ure 4-11. P.M Analysis Survey Results

O E E FOR OPERATORS

* \jVc measure O E E to monitor tlie condition of tlic equipment. * The point of using the OEE measure is to drive improvement. St~stainedimprovement requires a dedicated approach, with management support. \Vlien a problem returns, it often turns oirt that we have been treating the symptoms of the problem, but not dealing with its root cause. 5 \Vhy analysis is a useful tool tliat brings its closer to the root cause. *Autonomous maintenance refers to activities carried out by shopfloor teams to help stabilize basic equipment conditions and spot problems early. It cliangcs the old view tliat operators just run macliincs and maintenance people just fix them. Along with preventive mairitcnarice, a ~ ~ t o n o m o umaintes nance activities lielp raise O E E by maintaining proper opcrating conditions, and stabilize it by detecting ,tbnormalities before they turn into losses. Tlirougli tlie steps of autonomous maintenance, shopfloor employees . . work with inaintcnancc technicians arid engineers toward a common goal-more effective eqi~ipment.

-

f~ocuseclequipment and process improvement is the 'TPR4 pillar that deals mod directly with improving equiprncnt-related losses. Autonomous niaintenance and preventive maintenance improve OEE to a certain level, then help maintain basic opcrating conditions to stabilize the OEE. To raise O E E beyond this stabilized Ievcl, companies apply focused irnpro\wnent. Focriscd improvement involves targeted projects to reduce specific losses, carried out by cross-f~tnction;tlteams tliat include people with skills or resources an improvement plan might require.

IMPROVING OEE

It's good for companies to attain a basic "fitness" level with autono~iiousmaintenance and preventive maintenance before launching focused improvement projects to address specific weaknesses.

* Foci~sedimprovement teams use a range of approaches, including approaches that address specific e q ~ ~ i p m e n t related losses. Setup and adjustment time is an improvement target for OEE, since it reduces the time in which the machine is available to make products. Shigeo Shingo invented a changeover improvement system called single-minute escliange of die, or SMEU. 'This sysLen1 gives a three-stage approach for sllortening setup: Stage 1: Separate intcriial and exiernal setup Stage 2: Convert internal setup to external setup Stage 3: Streamline all aspects of setup The quality rate is an element of OEE. Many conipanies think h a t they are addressing quality issues through product inspection that catches defects before they leave the factory. In reality, liowever, this kind of inspection does not eliminate defects. To address random errors that cause defects, Shigeo Sllingo cleseloped the Zero Quality Control (ZQC) mistake-proofing system m

Z Q C prevents defects by catching errors and nonstandard conditions before they turn into defects. It ensures zero defects by inspecting for proper processing conditions, for 100 percent of the work, ideally just before an operation is performed. If an error is discovered, the process shuts down and gives immediate feedback. h4istake-proofing often relies on sensing meclianisms called poka-yoke, wliich check conditions antoniatieaily and signal when problems occur.

O E E FOR OPERATORS

0

0

'l'lre key to effective mistake-proofing is determining \vhcn and where defect-causing conditions arise and then figuring out how Lo detect or prevent these conditions, every time.

fJ-lvl analysis is a tool for systematically uncovering arld Lesting a11 the possible factors that could contribute to a clrronic problem.

* T h e "P" in P-A4 analysis stands for "phenomenon"-the abnormal event we want to control. It also stands for "physical"-the perspective we take in viewing the phenomenon. "M" refers to "meclianism" and to the "4Ms"-a frametvork of causal factors Lo esainine (Machine, Menl\%men [operator actions], Material, and Method). T h e essence of P-I1.I Analysis is to look systematically at every detail so no physical phenomena, underlying conclition, or causal factor is rnissetl. T h e basic steps of P-1\11 analysis are 1. I'hysically atlalying chro~ricproble~ns:~ccordingto the machine's operating principles

2. Defining the essential or constiluent conrliliorrs unclerlying the abnormal phenomena 3. Iclentifying all factors that contribute to thc phenomena in ternis of h e Nvl fr:~mcwork *After going through time steps, the team survevs for the presence of these factors, then tests improvement actions.

* 1'-h4 analysis is an advanced tool because it requires more time, resources, and expertise than 5 Wliy analysis. REFLECTIONS Now that you have completed this chapter, take five minutes to think about these questions and to write down your answers: What did you learn from reading this chapter that stands out a s particularly useful or interesting? Do you have any questions about the topics presented in this chapter? If so, what are they?

CHAPTER 5

1 Figure 5.1. Reflect on What You've Learned and What Is Most Useful to You

Reflecting on What You've Learned An important part of learning is reflecting on what you've learned. Key Paint

Without this step, learning can't take place effectively. That's why we've asked you at the end of each chapter to reflect on what you've learned. And now that you've reached the end of the book, we'd like to ask you to reflect on what you've learned from the book as a whole. Take ten mini~testo think about the following questions and to write down your answers. \\%at did you learn from reading this book that skands out as partieularly useful or interesting? What ideas, concepts, and tccllniques liave you learned that will bc most useful to you as your company applies overall equipment effectiveness and TPM? I-low will tlicy be itsefnl? What ideas, concepts, and techniques have yot~learned that will be least itseful as you apply OEE and TPM? \Vhy won't they be useful? Do you liase any questions about OEE or 'i'l'M? If so, what are they?

I

REFLECTIONS A N D CONCLUSIONS

Opportunities for Further Learning Here are some ways to learn more a b o ~ t overall t equipment effcctiveness and TPM: l'ind other books, videos, or trainings on this subject. Several are listed on the next pages. now-to s~sp.i

lrivestig;~tesofhrare ll~atcan help you record OEE data for reporting.

* If your conipanp is already using OEE or implementing TPM, visit other clepartments or areas to see how they are applying the ideas ;tnd approaches you have learned about here. Find out lmw o t l m cotnpanies have applied O E E :incl used it for irnpro\wnent. You can do this by reading ruagazines, newsletters, and books that cover OEE, other aspects ofTPM, a d lean manufacturing, as \veil as by atlending conferences and se~ni~tars that share implementation esamples and pointers.

Conclusions Overall equipment effectiveness is more than a set of measurem e n t steps. Used to its polential, it is a f ~ ~ n d a m e n tapproach al for improving the manufacturing process. We hope this book has given yo11 a taste of how and why this approach can b e helpful I your work. and effective for ~ O L in

I

CHAPTER 5

Additional Resources on TPM, OEE, and Equipment-Related Losses Training and Consulting One of the best ways to learn how to use OEE is to apply it under the gtiiclance of an espert. Trainers can bring vou through the steps of implementing TPh4 and applying O ~ toEyour equipment; experienced consultants can help you address specific issues in your plant. Productivity, Inc. provides training and consulting to support team-based TPh11 implementation.

Packaged Education and Support Packaged education is not a substit~itefor training or iniplementation with an expert, but it can lielp prepare people for implementation, and give inforniation 011 specialized topics. Productivity, Inc. offers a wide range of packaged education and support materials related to TPM, OEE, and equipment-related losses, OEE Software

Arno Koch, OEE Toolkit: Pructiccrl Sofhre for Meusuring Overall Equipment Effectiveness (Procluctivit): 1999)-A software package originally developed by a TPhiI consultant and prograrnnier to meet his clients' need for a cost-effective way to capture and report OEE data. It features an easy-lo-use interface for eonfiguration and data entry, a wide range of printable color-coded graphs, and a complete user's manual with guiclance for defining what to measure. A demonstration CD-ROM is avail;ible. TPM and OEE

hlasaji Xajiri and lit~niioGotoh, i\utonornous Maintetlunce in Sew1 Steps: Itnplementing TPAd for the Shopfloor (Procluctivit), 1999)-The most conipreliensive book available in English for planning and managing a complete aulonomous maintenance program. (Previously published as TPhd Implen~cntation.) Japan Institute of Plant Maintenance, ed., Autonomons Maintenance for Operators (Produchity, 1997)-h Sliopfloor Series book on key a~rlonomousniaintenance activities. Topics include cleaninglinspection, lubrication, containment of contaniination, and one-point lessons related to maintenance.

..

R E F - E C T I O. NS Ah0 C O N C L U S I O N S

J a p i Institute of Plant Rlaintenance, ed., TPM for Eveiy Operator (Productivity, 1996)-This Shopfloor Series book introcluces basic concepts of TPM, with emphasis on tlie six big equipment-related losses and OEE, autonomous maintenance activities, and safety. Kunio Shirose, ed., 'J'PM Tearr~Guide (Productivity, 1995)-A Shopfloor Series book that teaches how to le;d '1'PM team activities in the tvorkplace. It includes a section on developing and presenting project reports, and offers guidance w t h teaunwork issues. Kunio Shirose, ?'PA4 for Wbrkshop Lectclers (Procluctivity, 1992)Describes tlie liands-on leadership issues ofrl'Phil iml~lenicntation for shopfloor 7'PM group leaders, wit11 case studies and practical examples to help support autonomous maintenance activities. Cliarles J. Robinson and Andrew P. Ginder, imple~nentingTPM: The North i\merican Espcrierlce (1'rocIuctisity, 1995)-Describes how TPM fits into an overall manufacturing improveruent stmtegy for Western companies. A real-world perspective on what works and what doesn't, and an eclucational tool lor middle and upper managen~ent.Chapter topics include OEE, autonomous maintenance, ancl iniplenlenting TPM in a u~iionenvironnicnt. Naclii-F~~jikoshi Corporation, ed., 'iiaining for TPM: A i\ilanrr{actrrring Success Story (Productivity, 1990)-A classic case stucly oFTPM inipleiiientation at a world class manufacturer of bearings (a winner of the prestigiotts I'M Prize). This is the cornpletc story of how tlw company eliminated 90 percent of equipment-related losses in just LIiree years. Kunio Shirose, et al., 1'-Ad i\nuiysis: An i\dvanced Step in TPM In~plementcltion(Prodrtctivity, 1995)-Describes an effective step-by-step nicthod for analyzing and eliminating recurring ecpipment problems caused by multiple or complex faclors. This is tlie best resource in English, for this aclvanccd problen1solving approach that was introduced in Chapter 4 of this book Tokutaro Suzuki, ed., ?'PA4 in Process inclustries (Productivity, 1994)-Adapts TPM measures ancl activities for tlie specific needs of process and large-equipniet~t-baseclindustries. Tel-KI'raio, TI'ICI video series (distributed by Productivity)An inforniative ovenkw series in four programs: Introduction, Overall Equipment Effectiveness, Preventive Maintenance, arid

i

CHAPTER 5

l'redictive h4aintcnancc, plus a l%cilit:~tor'sGuide (includes 'fI'M Pilot l%wchart and overhead transp;~rencies). Qulck Changeover

Productivih: Development Team, Quick Changeover fix Operutors (~roductivhy,1996)-A Shopfloor Series book that describes Shingo's three stages of changeover inilxo\wnent with examples and illustrations. Sliigeo Shingo, A Re)folutioriin i\/lanrr{act~rring:The SMED System (Productivity, 1985)-A classic book for managers that tells the story of Shingo's SklED Systern, descriltes ho\v to implenlcrit it, and provides many cliangeo\w i~iiprovementexamples. Zero Quality Controi and Poka-Yoke (Mistake-Proofing)

Productivity Development Team, i\~listuke-Proofi12g Operutors (Productivity, 1997)-A Shopfloor Series book that clescribes the basic theory behind mistake-proofing and introduces i~oku-yoke systenis lor preventing errors that lead to defects. Sliigeo Sliingo, Zero Quulity Control: Source Irlspection cmd the l'o'oka-Yoke Systerri (Productivity, 1986)-A classic book for managers and engineers descrilting liow Sliingo developed his Z Q C approach. It includes a detailed introduction to poka-yoke devices a ~ i dmany examples of their application in different situations. NI