Since publication of the first edition in 2004, risk-based approaches to maintenance and reliability have moved firmly to the forefront of good practices. Two processes, Risk-Based Inspection and Instrumented Protective Functions, have been available for a number of years; they have been further developed and are now established as “must use” techniques. Along with Reliability Centered Maintenance, they provide an integrated suite of readily usable and useful techniques for the maintainer.
Many maintainers find themselves in businesses where the assets are unreliable, profitability is poor, and budgets are under pressure. The financial crisis of 2008 and its aftermath have made matters much worse. In response, we have provided some recipes to address these issues in the form of a new chapter in this edition. New sections in Chapter 10 explain and give clear guidance on the two risk-based processes mentioned above.
In Chapter 8, we have added accounts of the Longford (1998), Columbia (2003) and Sayano-Shushenskaya (2009) disasters. These reinforce the evidence for the event escalation theory explained in Chapter 9.
As is the norm with new editions, we have taken the opportunity to do some housekeeping. Internet website references (URLs) seem volatile and a few of the earlier references are no longer valid. Some books references are also outdated, as new publishers have taken over and ISBNs have changed. These are now corrected.
There is one other significant change – the book summary has been expanded and has now become a new chapter. Apart from the usual corrections and additions, the remainder of the book remains largely faithful to the first edition.
I welcome feedback from everyone using this book. Please write to me at the publisher’s email address: [email protected]
V. Narayan
Aberdeen, Scotland
The traditional view of the general public towards maintenance is one of elegant simplicity. Their contact is often limited to automobile or appliance repair workshops. From this experience, maintenance appears to be an unavoidable activity that costs money and takes time. The view held in the board rooms of industry appears to match this perception.
Good news is generally not news at all, so people only tend to think of maintenance when things go badly wrong. The moment there is a major safety or environmental incident, the media come alive with news of the maintenance cutbacks, real or imaginary, that have allegedly contributed to the incident. Think of what you saw on TV or read in the newspapers after any of the airline, ferry or industrial disasters, and you will readily recognize this picture.
What do we actually do when we manage a business? In our view, we manage the risk—of safety and environmental incidents, adverse publicity, loss of efficiency or productivity, and loss of market share. A half century ago, Peter F. Drucker1, a well known management guru, said:
“It is an absolute necessity for a business enterprise to produce the profit required to cover its future risks, to enable it to stay in business and to maintain intact its wealth producing capacity.”
This is as valid today as it was then. In the maintenance management context, the risks that are of concern to us relate to safety or environmental incidents, adverse publicity, and of loss of profitability or asset value.
We will examine the role of maintenance in minimizing these risks. The level and type of risks vary over the life of the business. Some risk reduction methods work better than others. The manager must know which ones to use, as the cost-effectiveness of the techniques differ. We will look at some of the risk reduction tools and techniques available to the maintainer, and discuss their applicability and effectiveness.
Risks can be quantitative or qualitative. We can usually find a solution when dealing with quantified risks, which relate to the probability and consequence of events. Qualitative risks are quite complex and more difficult to resolve, as they deal with human perceptions. These relate to peoples’ emotions and feelings and are difficult to predict or sometimes even understand.Decision-making requires that we evaluate risks, and both aspects are important. The relative importance of the qualitative and quantitative aspects of risk varies from case to case and person to person. Even the same person may use a different recipe each time. We should not categorize people or businesses as risk-seeking or risk-averse. It is not merely a mindset; the situation they face determines their attitude to risk. All these factors make the study of risk both interesting and challenging.
In this book, we set out to answer three questions:
Why do we do maintenance and how can we justify it?
What are the tasks we should do to minimize risks?
When should we do these tasks?
We have not devoted much time to the actual methods used in doing various maintenance tasks. There are many books dealing with the how-to aspects of subjects such as alignment, bearings,lubrication, or the application of Computerized Maintenance Management Systems. Other books deal with organizational matters or some specific techniques such as Reliability Centered Maintenance. We have concentrated on the risk management aspects and the answers to the above questions.
Throughout this book, we have kept the needs of the maintenance practitioner in mind. It is not necessary for the reader to have knowledge of systems and reliability engineering. We have devoted a chapter to develop these concepts from first principles,using tables and charts in preference to mathematical derivations. We hope that this will assist the reader in following subsequent discussions. Readers who wish to explore specific aspects can refer to the authors and publications listed at the end of each chapter. There is a glossary with definitions of terms used and a list of acronyms and abbreviations at the end of the book.
We believe that maintainers and designers can improve their contribution by using reliability engineering theory and the systems approach, in making their decisions. A large number of theoretical papers are available on this subject, but often they are abstract and difficult to apply. So these will remain learned papers, which practitioners do not understand or use. This is a pity because maintainers and designers can use the help which reliability engineers can provide. We hope that this book will help bridge the chasm between the designers and maintainers on the one hand, and the reliability engineers on the other. In doing so, we can help businesses utilize their assets effectively, safely, and profitably.
1 The Practice of Management, page 38, first published by William Heinemann in 1955. Currentedition is published by HarperBusiness, 1993, ISBN 0887306136.
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