https://ebookmass.com/product/quality-management-in-
Ioannis Anastopoulos
https://ebookmass.com/product/biomass-derived-materials-forenvironmental-applications-ioannis-anastopoulos/
ebookmass.com
Quality Management in Plastics Processing
Strategies, targets, techniques and tools
Robin Kent
Tangram Technology Ltd
Elsevier
Radarweg 29, PO Box 211, 1000 AE Amsterdam, Netherlands The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, United Kingdom 50 Hampshire Street, 5th Floor, Cambridge, MA 02139, United States
© 2016 Elsevier Ltd. All rights reserved
No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions.
This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein).
Notices
Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary. Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility.
To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein.
Library of Congress Cataloging-in-Publication Data
A catalog record for this book is available from the Library of Congress
Library Cataloguing-in-Publication Data
A catalogue record for this book is available from the British Library
ISBN: 978-0-0-8102-082- 1
For Information on all Elsevier publications visit our website at https://www.elsevier.com
8 Design quality management....................................................227
8.1
8.9
8.10
8.11
Chapter 1 Introduction to quality management
Quality management was one of the most discussed topics in manufacturing industry in the late 20th century. Many plastics processors embarked enthusiastically on the pursuit of the ‘Holy Grail’ of quality and many companies are still trying to make sense of the confusion surrounding quality. The results for many companies have been disappointing and they are still confused about what quality really means and how they achieve it.
In a sense, this was because the discussion was diverted by the mechanics of implementing formal quality systems such as ISO 9001, either in the mistaken belief that these would deliver quality or simply to conform to the requirements of suppliers or specifications. The implementation of statistical methods that could actually deliver quality through effective process control became secondary to the filling out of forms to satisfy the requirements of the systems.
Thirty years ago, quality management and statistical process control were the ‘in things’ and there was great interest and activity in the subjects but today little has really changed at the grass roots level.
At many of the plastics processors that I visit, quality management still consists of a few final inspectors and the mention of statistical process control still draws blank looks.
This really has to change if you are going to be a successful plastics processor in the future.
At many sites, the real basics of quality seem to have been missed and have been
substituted with lots of forms but little real management information or involvement. In this book we will go back to basics to provide the essentials for plastics processors in an easily accessible format.
This chapter looks at quality management in a broad sense to put the problems in perspective and to allow actions to be effectively targeted. It is designed to provide the essentials of the management framework for quality management.
Readers should not be tempted to rush into the practical aspects of quality management without first understanding the management framework.
“Of course we believe in quality - look at all the inspectors we employ.”
1.1 Wherewearegoing
The destination
One problem at many sites is that they know that they want to have quality but they really have no idea of the steps that they have to take to get there. They set off on the journey to quality with no real planning about where they want to go, why they want to get there (if anywhere), how they are going to go about it and how they will measure the progress they are making (if any).
Some sites set off by installing a ‘quality system’ (of any flavour) in the faint hope that this will somehow magically deliver quality, some install complex SPC systems, some increase the numbers of inspectors and others simply subject the quality manager to various arcane management tortures.
All of these partial and disjointed measures will inevitably fail. Some will fail more miserably than others, but all are eventually doomed (particularly subjecting the quality manager to management torture - as I am sure some of the readers will know from direct experience).
Even if a site has an operating and relatively successful quality system, there is always a need to improve quality and every site needs a plan (a road-map) to define where they are and where they want to be. Quality is often poorly defined (see Section 1.3) but still needs a road-map for the actions to be taken. The figure opposite shows some of the major areas, the processes and tools used, the benefits from using the processes and tools and the overall results of a properly functioning quality system.
This is about the whole company
A major issue is that quality is still sometimes seen as a ‘bolt-on’ to the other operations of the company. It is seen as a ‘good thing’ for the good times but optional in the bad times. The reality is that ‘quality’ needs to permeate the complete operation of the company. It is not a ‘production’ issue, it is a management issue for the whole company.
Collis Potter Huntington (see sidebar) was determined that the Newport News shipyard would be known the world over for ‘good ships’ and this philosophy has been consistent since 1886. The company is still a major supplier of ships to the US Navy even when other shipyards around the world have failed - the focus on ‘good ships’ has been the ethos to drive the company forward. How many other companies could make such a statement and live by it? How many other companies have been around since 1886?
Focusing on profit alone may make a company profitable in the short-term but, as too many companies have found out, does not guarantee that the company will survive in the long-term. Focusing on quality will not only deliver ‘good ships’ but also sustainable long-term profits. This means that companies need to see quality not as a cost but as a benefit and to realise that improving quality can also improve profits in both the short and the long-term.
The road-map
The road-map identifies the wide range of skills and activities that are necessary to achieve quality and even this is limited by space. The road-map shows the type of things that you will have to do to really achieve quality. It is not simply about systems or SPC or any other single thing. Specifically, it is not only about production. It is about the whole company and it is about a mind-set that says ‘quality is our guiding principle’ and that this principle can deliver both sustainable profits and continued employment.
The road-map covers all areas of a company’s operations from people (and their training) through product design, sales/marketing and production. The implementation of an effective quality management system (see Chapter 4) impacts every aspect of a company’s operations. This is not for the fainthearted but the rewards are more than worth the effort.
• Tip - None of the actions in the roadmap are ever completed. Get used to continual improvement.
“Alice: Would you tell me, please, which way I ought to go from here?
The Cheshire Cat: That depends a good deal on where you want to get to.
Alice: I don't much care where.
The Cheshire Cat: Then it doesn't much matter which way you go.
Alice: ...So long as I get somewhere.
The Cheshire Cat: Oh, you're sure to do that, if only you walk long enough.”
Lewis Carroll, Alice in Wonderland
“We shall build good ships here; at a profit if we can, at a loss if we must, but always good ships.”
Collis
Potter Huntington, Newport News Shipbuilding
The quality road-map
Improved quality can deliver many benefits but it needs a road-map of the available processes and tools to get the best results.
Chapter 1 - Introduction to quality management
1.3 Whatisquality?
Defining quality
Quality means many different things to different people and the apparently simple question ‘What is quality?’ is not always easy to answer.
When most people are asked to name a ‘quality car’ they will initially nominate an expensive car. This is due to the common confusion between ‘expensive’ and ‘quality’ and the linking of the two. When asked how they would rate an expensive car that always broke down then they will reconsider the question.
The reality is that an expensive car is not always a quality car. Price is a vital factor in assessing quality because we do not expect the same features or performance from a low-cost car. Our perception of quality is inevitably linked to the cost of the product and we always link quality and cost.
There are, in fact, a multitude of definitions of ‘quality’ (see top right) and a company can choose the one that best suits their needs. It is also important to realise that the definition of quality is not static, it is always transitory - the highest quality product of today can be an ‘alsoran’ product of tomorrow because of changes in competing products and prices. As the product and process environment changes so does the apparent quality of the product and process.
What was considered a ‘quality’ product in 1995 is definitely no longer a quality product in 2015.
• Tip - The customer’s view of quality will change with time. Companies must be prepared to change too.
Changing definitions
The initial definitions of quality were generally framed in terms of ‘meeting specifications’, ‘meeting expectations’ and ‘customer satisfaction’. This was a challenge in itself for many companies at the beginning of the quality revolution.
Improvements in quality levels and changes in society’s expectations have led to additions to the concept and definition of process and product quality. Current definitions look at ‘exceeding’ expectations and additional areas such as sustainability and other ‘green’ issues.
The definition of quality varies:
What gives complete customer satisfaction.
Fitness for purpose and valuefor money.
Conformance to requirements.
Conformance to specification.
Value for money = Quality for price.
‘On target with minimum variation’ (Genichi Taguchi).
‘Right First Time’ (Frank Price).
When the customer returns, not the product.
When the product is what the customer wants it to be.
The degree of excellence of something (Oxford Dictionary).
When a product or service meets or exceeds its design specification.
The whole package, not just what is in the box.
Quality
Management
Coordinated activities to direct and control an organisation with regard to quality (ISO 9000:2005).
Quality Assurance:
Part of quality management focused on providing confidence that quality requirements will be fulfilled (ISO 9000:2005).
All activities and functions concerned with the attainment of quality (BS 4778:1991).
The activity of providing, to all concerned, the evidence needed to establish confidence that the quality function is being performed adequately (Juran).
Quality Control:
Part of quality management focused on fulfilling quality requirements (ISO 9000:2005).
The operational techniques and activities that sustain the product or service quality to specified requirements. It is also the use of such techniques and activities (BS 4778:1991).
The process through which we measure actual quality performance, compare it with standards, and act on the difference (Juran).
Quality Improvement:
Part of quality management focused on increasing the ability to fulfil quality requirements (ISO 9000:2005).
Quality System:
The organisation and structure, responsibilities, activities, resources and events that together provide organised procedures and methods of implementation to ensure the capability of the organisation to meet quality requirements (BS 4778:1991). Chapter 1 - Introduction to
often this was accompanied by a decrease in quality and the need for inspectors and quality departments.
The need to control processes to control product quality was first recognised by Shewhart at Bell Laboratories in the 1920’s. Shewhart used process statistics to control the product and created the ‘control chart’ and much of the basis for Statistical Process Control (see Chapter 5). At the same time, Fisher was investigating the design of experiments and how to reduce the number of experiments to analyse crop experiments (see Section 8.15).
In the early 1930’s Dodge and Romig (also at Bell Laboratories) developed the basic concepts of Acceptance Quality Levels (AQLs) such as acceptance sampling, including ideas such as consumer's risk, producer's risk, double sampling, lot tolerance percent defective and average outgoing quality limit (see Chapter 6).
During World War II, the need for consistency of production (millions of bullets must all fit millions of guns) led to efforts to improve production consistency across the world. Shewhart’s SPC techniques and Dodge and Romig’s AQL techniques were used to dramatically improve consistency (Mil-Std-105) but, at the end of the war, these were abandoned as companies went back to their ‘superior’ engineering approach.
Industrial relations
In parallel with the scientific management movement, there were also significant developments in the field of industrial relations as psychologists tried to repair the damage done by the dehumanising effects of scientific management. McGregor, Herzberg and Maslow all worked to identify what motivated workers and what could be done to improve worker satisfaction and hence quality of output.
The quality ‘revolution’
The quality revolution in the West was driven by the earlier quality revolution in Japan. After the devastation of World War II, efforts to reconstruct Japanese industry included technical assistance and part of the assistance was with management. Deming and Juran both worked with Japanese industry to improve quality and developed a unique blend of technology and management techniques that revolutionised Japanese
manufacturing. The Japanese did not only rely on Deming and Juran, Japanese workers such as Ishikawa, Kano, Taguchi and Shingo all contributed to developing not simply statistical techniques but many of the tools and techniques that are now considered essential to quality management.
Manufacturing industries
The rapid rise in quality of Japanese products took the West by surprise and decimated whole sectors of Western industry, particularly the automotive and electronics industries.
The Western response was swift and the 1980’s saw a rapid adoption of Japanese techniques (with variable results) in an effort to save the Western industrial base. The Total Quality Management (TQM) movement began in the USA and was championed by leaders such as Crosby who pioneered ‘Right First Time’ through his book ‘Quality Is Free’. This movement spread throughout the world and the result was the ‘quality revolution’ of the 1980’s and 1990’s.
Service industries
The TQM movement started in manufacturing but the techniques were just as applicable to service industries (see Chapter 11) and they were used to great effect in the late 1990’s.
Unfortunately, TQM became seen as another management ‘fad’ (largely because management never really implemented it properly) and it has largely been replaced by the ‘6-Sigma’ movement. This was developed at Motorola and famously implemented at General Electric. It uses many of the standard statistical tools (rebranded for a new generation) with a high reliance on reducing variation in the process.
Quality management systems
Alongside the TQM development of tools and techniques there was a movement to institutionalise quality via the use of management systems. Initially developed in the UK in the 1970’s (as BS 5750), the systems approach rapidly went international via the ISO 9000 suite of standards (see Chapter 4). Not content with institutionalising quality, the standards creators have migrated the same approach to other areas such as environment and energy.
Our concept of quality has changed with time.
The methods and techniques are important but it is our perception that makes the difference.
The development and transition of quality management into the service industries seems to have taken manufacturing industry by surprise. Manufacturing has always regarded quality as something that was relevant only to the physical product.
Perhaps the service industries have something to teach us about quality in the services that are an essential part of what we do?
Your competitors can buy the same equipment, buy the same materials at the same prices and even employ the same type of people that you can.
The only way to really differentiate yourself is to be better in quality and people by investing in both of them.
1.6 Theimportanceofqualitycosts
The terminology
In most books the terminology used is ‘the cost of quality’ or ‘quality costs’ and we will continue to use this for the sake of conformance with the existing literature. The problem with these terms is that they immediately imply that quality is a discretionary cost and that if you stop spending money on quality that your costs will decrease and profits increase. This also creates the impression that quality is a ‘burden’ on the company.
Nothing could be further from the truthif you stop spending money on quality then profits will decrease and eventually the company will cease to exist.
At this stage we will look only at the size of the costs and the opportunities for improving the overall financial performance of a company. The cost of quality will be dealt with at greater length in Chapter 3.
The magnitude of the costs
For the majority of plastics processing sites, the cost of poor quality is in the region of 20% of sales. This cost comes mainly from failure costs, i.e. where the product does not meet the requirements. This failure cost can be either an internal cost (if the product does not reach the external customer) or an external cost (if the product is dispatched to the external customer). Failure costs generally dwarf the other quality costs such as appraisal costs, i.e. inspection costs, and prevention costs, i.e. what we do to stop failure happening in the first place.
The typical ‘real’ costs are shown on the right and these costs will usually be significantly higher than the profit margin for a plastics processing company. Despite this, few sites are able to accurately (or even inaccurately) quantify and allocate their real quality costs. A basic understanding of the quality costs at any site will provide a real driving force for quality improvement. The exact costs for each site will depend on the operations but the ‘real’ costs will be approximately correct for the majority of sites.
• Tip - A simple walk around to look for reworked and scrapped material will often identify quality costs that the site
has never really considered before.
• Tip - Look in the regrind areas, skips and scrap bins for a real education.
The magnitude of the savings
The possible savings from good quality management are in the region of 50% of the current quality costs for most plastics processing sites. Savings of this magnitude represent up to 10% of sales and this is significantly higher than the profit margin for most plastics processors. These savings can be delivered virtually irrespective of the industry sector or process used. The process used makes
Nobody wants to do it wrong and have to do it again but at many sites this is what happens day after day after day.
Quality costs are generally 5-25% of turnover.
Total cost of quality ≈ 10% of sales.
Appraisal Prevention
Transformation through allocation of resources Decrease in failure costs
Increase in prevention costs Decrease in appraisal costs
An approximate division of the cost of poor quality
In most cases, the total cost of quality is between 5-25% of sales. This easily exceeds the profits of most plastics processing companies and can be up to 5 times the profits. This can be transformed by re-allocating the resources.
little difference in the potential savings - it is management that makes the difference. These savings are possible by changing resource allocation from dealing with the product after it has failed to preventing the product failing in the first place. Increasing resources in prevention may cost more money initially but greatly reduces later failure costs.
The payback
The majority of the savings can be delivered through a balanced combination of no-cost, low-cost and investment (maintenance or capital) actions. The average payback for most investments in quality management is less than 12 months. This is true even when the payback is calculated using the costs for internal management efforts.
This type of payback makes investment in quality management extremely attractive from a purely financial point of view. Not many capital investment projects achieve a payback of less than 1 year and continue to deliver the benefits virtually indefinitely. Yet many sites fail to carry out attractive quality improvement projects because they have a faulty understanding of how quality can be improved. They continue to spend money on appraisal costs and accept the failure costs because these are regarded as inevitable. Capital investment proposals are still primarily presented based on direct labour reductions and rarely put forward based on reducing quality costs.
Straight to the bottom line
In many cases, a site’s quality costs are almost a discretionary cost, i.e. the site chooses to pay the cost of quality because it chooses not to do anything about it. Reducing the discretionary cost of quality at any site is directly geared to the profit of the site.
Any cost savings due to quality management translate directly to the bottom line and are shown as a direct increase in profit. Work in quality management is as valuable as work to reduce direct labour and in many cases the savings are more easily achieved because previous work to reduce direct labour has already removed the easy wins.
Better than increased sales
When the cost of quality is reduced, it adds directly to the bottom line -
something that increasing sales does not do. If the quality costs are 20% of the turnover and the profit margin is 5% then reducing quality costs by 25% (equivalent to 5% of the turnover) is the same as adding 100% to the profit. To achieve the same result through increased sales would require doubling the sales - not an easy task. What would your site do to gain new business that increased turnover and profit by 100% if you knew that:
• Your competitors couldn’t stop you getting the business.
• The business was effectively guaranteed.
• The business required only internal effort.
• The business was low-risk and had a payback of less than 12 months.
• The business would continue into the future and probably increase in value. Most sites are enthusiastic about gaining new business through increased sales. Yet when shown the opportunity to reduce quality costs and achieve the same results at the profit line, the same sites react with huge indifference. The saying is that ‘turnover is vanity, profit is sanity’ but unfortunately many sites still prefer the vanity of increased turnover to the sanity of increased profit.
Quality costs are the costs of not getting it right first time.
Reducing quality costs is the equivalent of new sales
If the net margin is 10% then every £1 saved by quality management produces the same profit as £10 of new sales. If the net margin is 5% then every £1 saved is the equivalent of £20 of new sales. Savings due to quality management areeasier to get than new sales and provide easy opportunities for increased profits.
1.7 Performanceindicators
How are you doing?
Performance indicators are a vital part of quality management and are essential for implementing and driving effective quality management. If performance indicators are not being prominently displayed, widely circulated, continually updated and widely discussed (at both the shop floor and board level) then attempts at real quality management will inevitably fail.
Performance indicators are needed to check that processes and systems are actually delivering improved quality and quantifying or measuring these results. The performance indicators chosen should not only provide information on the current status (relative to historical performance) but should also provide information on areas for potential improvement actions.
Indicators can be either internal or external, i.e. they can either reflect internal progress or external progress. Both types of indicators are valuable and necessary for a full understanding of quality management performance.
Internal indicators
Internal indicators use measures which are only relevant internally, i.e. they are not valued by the customer. Internal indicators are typically:
• Provided by the accounting or production function.
• Real and quantifiable numbers, e.g. cost, material or time based.
• Focused on internal improvement, e.g. quality savings are quantifiable but only relevant internally.
• Can (and should) be integrated easily into the regular company reporting process.
• Can be updated monthly or weekly.
Cost of quality (see Section 1.6 and Chapter 3) is a typical internal performance indicator and is one of the best measures for driving improvement, provided the costs being reported can actually be influenced by the people who are given responsibility for them (see below). Other internal performance indicators include reject rate, scrap rate, machine downtime, etc.
External indicators
External indicators use measures which are relevant from the customer's point of view. They are the 'voice of the customer'. This does not mean that they are less valid or that they should not be valued, in fact they can be the most valuable of all performance indicators. They provide essential feedback on performance as seen from outside the company. External indicators are typically:
• Provided by external customer surveys or other feedback, e.g. complaints data.
• Perception based rather than real and quantifiable numbers.
• Tip - If external customer feedback is numbers based then it usually comes as a surprise and is usually bad news. (Otherwise they wouldn’t be recording it.)
• Focused on improvement of external relations with customers and suppliers.
• Are more difficult to integrate into the regular company reporting process. This does not mean that they should not be integrated, simply that it is more difficult.
• Are difficult to update monthly or weekly unless a sample of external customers is taken each month.
External indicators rely heavily on customer feedback and every company needs to establish some type of customer satisfaction scorecard for regular reporting.
• Tip - External indicators do not quantify savings and the results are often difficult to quantify.
Customer scorecards
Setting up a customer scorecard involves:
• Defining the customer.
• Defining the main customer experience/ features. There should be no more than 7 features. Be lateral in thinking about what the customer wants.
• Setting a scale of 1-10, good to bad or other relevant measure.
• Trialing the initial scorecard with customers.
• Rolling the scorecard out to all customers.
1 complaint in 100 orders does not mean 99 satisfied customers!
It is deeper than that.
Try the ‘phone-in’ test.
Call your company and see how it feels to be a customer. This would be a good idea for those companies who use telephone menu systems. These always seem to be designed so that you cannot ever get to where you want to go or speak to a real person. They may sound a good idea and save money but have you ever asked your customers about them?