Defence Electronics. Standards and Quality Assurance

368 Pages·1991·28.122 MB·English

by  Ray Tricker (Auth.)

Defence Electronics
Standards and quality assurance
Ray Tricker
U T T E R W O R TH
E 1 N E M A N N
Newnes
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First published 1991
© Ray Tricker 1991
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British Library Cataloguing in Publication Data
Tricker, Raymond L.
Defence electronics.
1. Military electronic equipment
I. Title
623.043
ISBN 0 7506 0095 0
Typeset by Key Graphics, Aldermaston
Printed and bound in Great Britain by Butler and Tanner
To Claire
Preface
One of the words most frequently used in This consumer requirement has, quite natu­
business nowadays is 'quality'. Nevertheless, rally, had a sort of knock-on effect. Manufac­
this term is often misused, misquoted and mis­ turers have had to pay even more attention
understood. So what do we mean by 'quality'? to the quality of their products than was
There are many definitions, but the most previously necessary. They have had to set up
accepted definition of quality assurance is 'the proper control systems; monitor all stages of
totality of features or characteristics of a the production process; and provide proof to
product or service that bear on its ability to the potential customer that the articles they are
satisfy a given need' (ISO 8402). selling carry a guaranteed - and in some cases
When people talk about the quality of an certifiable - assurance that they have achieved
object, they are normally referring to its excel­ the level of quality required. In other words,
lence, its perfection or its value. In reality, of the manufacturer has been required to provide
course, they should be talking about the degree some degree of quality assurance for his
that it fulfils its designed purpose and product.
conforms to the manufacturer's original specifi­ The current trend towards micro-miniatur­
cations. Referring to the quality of a single ization has meant that most modern products
article is fairly simple. Problems arise when have become extremely complex assemblies of
one has to talk about complex systems; it is components compared with a few years ago.
then very difficult to assess a level of quality. The result is that many more people are
Consumers (i.e. purchasers) have always had involved in the manufacture of a relatively
difficulty in choosing between different simple object, and this in turn has increased
products of the same type; in this age of techno­ the likelihood of a production fault occurring.
logical complexity, it has become almost Similarly, the responsibility for the quality of
impossible to do so without some form of all their work has also had to be spread over an
professional assistance. For this reason, increasing number of people; consequently, the
purchasers have tended to form organizations - manufacturer's guarantees of quality has unfor­
such as consumers' associations - whose tunately become less precise.
expertise can be relied on to critically examine Although the British Standards Institution
similar objects and grade them according to the (BSI) has been in existence since 1901 and has
level of quality that a particular manufacturer produced numerous regulations and standards
or supplier has achieved. covering most manufacturing and supply func­
The consumer, however, is not interested tions, until a few years ago there were no for­
only in the level of quality intended by the malized standards for assuring a manufac­
manufacturer. The consumer is far more con­ turer's (or supplier's) quality. Formal quality
cerned with the maintenance of the manufac­ procedures and guarantees were therefore
turer's quality level and the assurance that the required, and the military grasped the nettle -
article he is buying meets the quality standard as frequently happens in these cases.
that he was initially offered or recommended. The US National Aeronautics and Space
xxi
Preface
Administration (NASA), with its requirement organizations involved in quality assurance in
for the highest possible level of equipment reli­ the general field of defence electronics. This
ability was the first to produce a set of proce­ book is also intended to provide the reader
dures, specifications and systems. These with an indication of the way ahead - particu­
became known as the 'Mil' specifications. Man­ larly with respect to the forthcoming European
ufacturers, large and small, were required to single market and the growth in market
conform to these specifications if they wanted potential from Warsaw Pact countries.
to become part of the lucrative military market. A quick note with regard to the acronyms
The North Atlantic Treaty Organization that are used in this book. I have spent all my
(NATO), under American influence, then pro­ adult life in the Army, but I still haven't got
duced a series of quality assurance procedures used to the proliferation of acronyms that the
known as Allied Quality Assurance Publica­ military insists on using! This is not just a
tions (AQAPs). These publications were then failing of the military; it is an attempt to please
republished by the UK Ministry of Defence as everyone by simplifying lengthy titles into
the Defence Standard (DefStan) 05 series. something more manageable. I have always
Civilian firms and contractors also recog­ hated this, as I can never remember what all
nized the necessity for having manufacturers those acronyms really mean and I have to con­
abide by a recognized set of quality standards. stantly refer to a crib sheet. In fact I remember
The British Standards Institution adapted the one occasion when, as a project manager, I was
DefStan 05 series into a virtually identical set chairing an engineering meeting. We became so
of documents known as the BS 5750 series. bogged down with acronyms that in desper­
This series has been copied by others and is ation I suggested that we should include a 'D of
now identical to the European (EN 29000) and A' with the minutes of the meeting. Absolute
the international (ISO 9000) standards for silence - until someone dared to ask what a *D
quality systems. of A was. Rather pompously I told them that it
For anyone wanting to sell a product to the was a 'Dictionary of Abbreviations'.
military, these publications form essential With this in mind, and in order that chapters
reading. Together they provide an extremely can be read separately if required, as acronyms
comprehensive set of rules and regulations that are introduced the full title is given first. To
enable a manufacturer (or supplier) to set up assist readers, a 'D of A has also been included
viable quality assurance procedures and at the end of the book.
operate within their constraints. Throughout the book, reference is made in
Even though these publications are very brief to the contact points of various organiza­
comprehensive, there is still a requirement for tions. The full addresses are listed at the end of
whoever is trying to achieve the standards to the book.
have a broad background knowledge of the One final note. Certain technical terms and
subject - its terms, conditions, justifications usages in this book, although reflecting only
and requirements. It is the aim of this book to the masculine gender, are in fact the parlance of
provide that background in the form of a ref­ the field and should be interpreted to apply to
erence manual that will serve as an engineer's both sexes.
and manufacturer's guide to the standards and
xxii
Acknowledgements
To attempt to write any form of reference DOE; Julia Vellacott from PSA; Lawrence
manual always requires a great deal of research Herbert from Longman; Dr Donald Radley from
- and infinite patience from those being asked CODUS; Gillian Ingham from Croner; The
to 'fill in the details'. Secretariat of EOQ; Pergrine Rowse from ILI; D.
I would, therefore, like to gratefully E. Sminia, Mrs B. Peters and Petra Maas from
acknowledge the contributions, support and EFQM; Kjell Mellberg from Ericsson; Roar
assistance given to me by various members of Karlsen from EB Netcom; Martin de Zwarte
the military, government and industry. Many from Motorola; Phillipa Turner from DTI; R. J.
people have helped me in preparing this book Peacock from Resource; Mr C. Weaver and
and it would be an impossible task to name Herbert Hafner and N. L. Merritt from CECC;
them all. May I, therefore, be permitted to say a Richard Kay from IECQ; Andy Hase from Tech­
very big 'thank you' to all those people who nical Indexes; and J. Benoist from UTE.
cheerfully and unstintingly gave so much of More specifically I would like to thank Peter
their valuable time in the compilation of this Allen from the MOD Whitehall Library, John
book, but in particular mention: Linda Brockman from the MOD Library at Bromley,
Henshaw, David Mew, Miss H. P. Collins, Mrs Mrs P. Danvers and Mrs L. D. Terrett from BSI
A. M. Deighan, Yvonne Hibberd, Alan Chew, and most of all, my two 'typists' Claire and
Mr K. C. Nel, Graham Inett, Mr C. G. Lewis and Rozz for 'slaving over the hot keyboard' for so
Ken Robinson from MOD; Tracey Dodds from many hours.
Quality control and
1
quality assurance
The definition of Quality is internationally amount of supervision that a product is sub­
accepted as 'the totality of features and charac­ jected to so as to be sure that the workmanship
teristics of a product or service that bear on its associated with that product meets the quality
ability to satisfy a given need', or more simply level required by the design. In other words it is
'fitness for intended use' (ISO 8402). the control exercised by the manufacturers to
certify that all aspects of their activities during
the design, production, installation and in-
1.1 Definitions
service stages are to the desired standards.
(Figure 1.1).
At first sight the terms 'quality assurance 5 and Quality control is exercised at all levels. As
'quality control· appear very similar, and this all personnel are responsible for the particular
can be very confusing to the uninitiated. task they are doing, they are all quality con­
Perhaps it would, therefore, be worthwhile to trollers to some degree or other. Section chiefs,
spend a little time at this stage in defining because of their positions and responsibilities,
exactly what we mean by these terms. have more control over their own particular
manufacturing process and thus have more
control over the final quality. It is true,
1.1.1 Quality control
therefore, to say that all personnel are quality
Quality control (QC) is the 'operational tech­ controllers and that section chiefs are the prin­
niques and activities that are used to fulfill cipal quality controllers within their own par­
requirements for quality' (ISO 8402). It is the ticular section.
To meet
specified
requirements
Figure 1.1 Quality con trol
3
Defence Electronics
1.1.2 Quality assurance In a nutshell, quality assurance is concerned
with:
'Quality' is fitness for purpose. 'Assurance' is a
declaration given to inspire confidence in • An agreed level of quality
an organization's capability. Thus quality
• A commitment within a manufacturing
assurance (QA) is a declaration given to inspire
company to the fundamental principle of
confidence that a particular organization is
consistently supplying the right quality
capable of consistently satisfying need. It is a
product
management process designed to increase con­
• A commitment from a customer to the fun­
fidence in a product or service by consistently
damental principle of only accepting the
achieving stated objectives (Figure 1.2).
right quality product
• A commitment within all levels of the
Quality assurance is
company (supplier or customer) to the basic
principles of quality assurance and quality
all those planned and systematic actions nec­
essary to provide adequate confidence that a control.
product or service will satisfy given require­
ments for quality ... [It is an] assertion made to The main benefits of quality assurance are:
inspire confidence that a product has achieved
the highest standards and that its manufacture,
• An increased capability of producing a
modification or repair has been completed in an
product which consistently conforms to an
efficient and timely manner. Its purposes are:
agreed specification
(a) To provide assurance to the purchaser that the
• A reduction in manufacturing costs because
standard of workmanship within that firm is of
of less wastage and fewer rejects
the highest level and that an article leaving
that particular firm is above a certain fixed • A greater involvement and motivation of a
minimum level of specification. manufacturer's workforce
(b) To ensure that manufacturing standards are • An improved customer relationship
uniform between sections and remain constant through fewer complaints, thus providing
despite changes in personnel. (ISO 8402). an increased sales potential.
Product
Guaranteed
system
quality
Figure 1.2 Quality assurance
4
Quality control and quality assurance
1.2 Quality assurance during a
play a major part in setting the quality level of
product's life cycle the eventual product. If there is no quality
control in the drawing office, what chance is
As quality assurance affects the product there of quality on the shop floor? When the
throughout its life cycle, it is important that engineers are trying to manufacture something
quality assurance procedures are introduced to a set of drawings that have countless mis­
for design, manufacturing and acceptance takes on them, what chance is there of pro­
stages, as well as for in-service utilization ducing an acceptable item?
(Figure 1.3). These problems have been fully recognized.
Figure 1.3 Quality assurance during a product's life cycle
1.2.1 Design stage One of the requirements of national and inter­
national standards is for the design office to
Quality must be designed into a product before produce a procedures manual which describes
manufacture (Figure 1.4). Throughout the the routine procedures that are required to turn
design stage of a product (or service) the quality a concept into a set of functional drawings. In
of that design must be regularly checked. many ways this is very similar to a quality
Quality procedures must be planned and manual (see Chapter 3).
implemented so as to predict and evaluate the The procedures manual will cover such
fundamental and intrinsic liability of the pro­ activities as the numbering of drawings, autho­
posed design. rization to issue amendments, modifications,
Whether the responsibility for the design of a changes to drawings, the methods for removing
product rests purely with the supplier or the obsolete drawings, and the identification, cata­
purchaser, or is a joint function, it is essential loguing and maintenance of drawings. All of
that the designer is fully aware of the exact these aspects are, of course, extremely
requirements of the project and has a sound important in assuring quality within the
background knowledge of the relevant stan­ drawing office. Other actions that are required
dards, information and procedures that will include preparing business and performance
have to be adopted during the design stages. specifications; obtaining formal approval of the
This is very important, for the actions of the designs from the estimating, manufacturing
design office not only influence the mainte­ and development sections, together with the
nance of quality during manufacture but also marketing and sales divisions; setting up target
Defence Electronics
Figure 1.4 Design stage
dates and checking drawings; and ensuring that continually updated and amended. This infor­
the details are available of all the relevant stan­ mation (data) can then be used with standard
dards and specifications to be used during software programs and computer aided design
manufacture. facilities to produce lists, graphs and drawings.
As well as these procedures it is also nec­ The possibilities are almost endless.
essary for the drawing office to have complete Another responsibility of the design office is
listings of all the relevant components and to maintain contact with the manufacturing
their availability, acceptability and adequacy, department so that they can assist in the
and to be aware of all the advances in both analysis of failures, swiftly produce solutions
materials and equipment that are currently and forestall costly work stoppages. In order
available on the market today and that could be that the statistical significance of a particular
relevant to the product. failure can be assessed and the correct
It is imperative that the design office main­ retroactive action taken, it is essential that the
tains a close relationship with the manufac­ design department has access to all the records,
turing department throughout these initial failure reports and any other relevant data as it
stages so as to be aware of its exact require­ becomes available from the design office or
ments, problems, choices of components and shop floor.
so on. It can be so easy for the design office to The storage, maintenance and analysis of
make an arbitrary selection, but then find that reliability data will require the design
the size and tolerance are completely inappro­ department to follow the progress of the
priate for the manufacturer. product throughout its productive life cycle, to
Nowadays, of course, most design offices are analyse its many maintenance cycles and to
computerized and use processors to store their take due note of customers' comments. It is
records on disks so that the information can be obvious that the compilation and retention of
6