Failure Mapping

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Failure MappingA New And Powerful Tool For

Improving Reliability And Maintenance



Failure MappingA New And Powerful Tool For

Improving Reliability And Maintenance

by

Daniel T. Daley

Industrial Press Inc.

New York



Dedication

To my motherand father who helped create themap I followed through my life.



Table of Contents

Introduction ix

Chapter 1 Patterns and Relationships 1

Chapter 2 The Path to Failure 9

Chapter 3 Examples of Failure Mappingand Their Applications 35

Chapter 4 Naturally Occurring Elements 49that can be Enhanced byFailure Mapping

Chapter 5 Structured Assessment 85

Chapter 6 Characteristics Evaluated Duringa Failure Mapping Assessment 105

Chapter 7 Assembling a Failure

Mapping Process 121

Chapter 8 Conclusion 139

Appendix 143

References for Further Reading 155

Index 157



Introduction

Failure Mapping is a system that recognizes patterns ofevents or conditions that have a direct relationship with subsequentfailures. The ability to describe the meaningful elements of those

patterns with high accuracy and then to recognize the relationshipbetween them and a failure depends on the ability to capture sim-ple unadorned facts. This book describes a process that fills thoseneeds more completely than other approaches by detailed exami-nation of events, a process that is known as Failure Mapping.

Not too long ago, a company had, what was then viewed,as two competing reliability processes. One was Root Cause

Analysis (RCA) and the other was Reliability Centered Mainten-ance (RCM). Rather than being in competition in terms of value orusefulness, these processes were viewed as competing for thesame limited resources. The company had a number of reliabilityoptions and only a limited pool of individuals available to pursue thesolutions.

The people who supported RCA held the position that it

would provide a sure return on their investment in a short period oftime. The people who supported RCM argued that the opportunityfor improvement was much broader than could be effectivelyaddressed by RCA and that RCM would provide a much more com-prehensive solution. It turned out that both sides and neither sidewon. The RCA program that was implemented held that only asmall number of “true disciples” could act as RCA facilitators, sorather than being an “inclusive” process, it turned out to be an

“exclusive” process. The RCM program was a healthier, inclusiveprocess, but it was starved for the resources needed to make it areal success.

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Viewed from the perspective of someone in the reliabilitybusiness, the dichotomy described above is silly and wasteful of

resources and time. Both RCA and RCM are important tools andare critical elements of any comprehensive reliability program. Onthe other hand, we can use the competition to provide a usefulstarting point in analyzing both RCA and RCM for their strengthsand weaknesses. The argument described above is one that is notuncommon during the early days in the development of a compre-hensive reliability program for any company. The reason for theargument is not so much about people being perfectly happy withtheir proposed solution as it is about people being dissatisfied withthe alternative. If there was a perfect solution, they all believe theywould choose it.

STRENGTHS AND WEAKNESSES OF RCA AND RCM.

RCA is one of the most basic and reliable tools for identify-ing the true cause of any failure. Beyond that, RCA is probably thesingle best tool for teaching non-engineering personnel the rigorand discipline of the scientific method. This issue is critical for com-panies that depend on complex capital-intensive assets for theirsuccess, but where most employees do not have engineeringbackgrounds.

RCA is a relatively quick and sure technique for finding thecause and resolving troublesome problems. Drawbacks are thatRCA can be resource intensive and the results can address only

one specific issue. In some applications it is possible to extendwhat is learned from one study to a number of problems that sharea common cause, but that is more a matter of good fortune thandesign.

The greatest value stemming from RCA, that has generalapplicability, is broadening the ability of the organization to recog-nize patterns that contribute to failures and the relationships

between those patterns and specific ensuing failures. In a workenvironment that is not more than two generations from blamingfailures on “gremlins,” and one generation from having the attitude

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that “bad things happen.” It is critical that people clearly understandthat failures are the result of defects and defects result from specif-

ic preventable causes.

The biggest limitation of RCA is that it is very much after-the-fact. The solutions are identified long after the problem hasoccurred and the loss has been sustained. There is a saying that,“Once the cat is out of the bag, you need to think about dealing witha cat and not a bag”. RCA is very much a technique that deals withcats and not bags.

The RCM process is very comprehensiveand can be used to thoroughly address alldevices that experience failures in any sys-tem. RCM is highly structured and can betightly integrated with a variety of datasources. As with RCA, RCM can be helpfulin teaching individuals who do not havetechnical backgrounds the importance ofapplying the scientific method whenattempting to observe patterns that create defects, and how toassess the relationships between those patterns and the failuresthat result.

The main benefit of RCM is that it produces the most effec-tive program of predictive and preventive maintenance, and worksto harvest all the available inherent reliability of the system being

analyzed.

On the other hand, RCM has several shortcomingsincluding:

1. It is time-consuming and resource intensive.2. Without introducing some enhancements, the resulting

reliability is limited to the inherent reliability of the

system being studied.3. As with RCA, it is another process that deals with cats

rather than bags. Its results occur long after the fact.

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With both RCA and RCM, there is the same recurringtheme: dealing with cats and bags. Both these programs go into

action after an untoward event has occurred and the event hasusually happened some time in the distant past. Both techniquesare good and very helpful, but it would be better to have a processthat is capable of moving the line-of-scrimmage from after-the-factto real-time and to be able to act before the failure has an opportu-nity to occur.

So, looking at the good and missing features of both RCAand RCM, it would be helpful to describe the features of a processthat fills all those needs. The process needs to be:

1. Inclusive – it needs to involve the widest population forunderstanding and applying the scientific method indealing with defects that lead to failures.

2. Rigorous – it needs to produce results that will with-stand scrutiny.

3. Disciplined – it needs to be based on a well-definedprocess that participants can follow and that can beaudited when anticipated results are not beingachieved.

4. It needs to be done quickly, immediately after thefailure; at the same time that the defect is forming, orwhile the failure mechanism is at work.

5. It needs to be based on an accepted structure thatparticipants can apply in a manner consistent with

the accepted science of reliability.6. It needs to be comprehensive – it needs to be part of a

process that touches all systems and equipmentand not just a select few.

The process described by the requirements listed above isotherwise termed Failure Mapping. Failure Mapping is a techniquethat applies historical experience to create maps showing how fail-

ures occur, then it uses those maps to observe and intervene in thecycle of on-going deterioration and failure patterns to prevent fail-ures whenever possible and to minimize their impact when they

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cannot be avoided.

The objectives of this book are to:

• Describe the overall concept of Failure Mapping.• Understand where some elements of Failure Mapping

are already being used in systems used by an organiza-tion.

• Identify how to perform an assessment of the value thatmore rigorous Failure Mapping will provide to thecompany.

• Identify how a firm might go about implementing aFailure Mapping process.

As a professional who has been involved in the reliabilitybusiness for quite some time, the author believes that the processof Failure Mapping is the most exciting new tool to come down thepike for quite some time. As discussed in the paragraphs above,although not a replacement for either RCA or RCM, FailureMapping offers many of the characteristics of both those process-es, and a solution to cure their shortcomings.

In this book, the author has taken the liberty of creating avirtual organization that shares among its members a culture thatis based, in part, on an understanding of the value of FailureMapping. Rather than having a vague sense that gremlins causefailures, or that bad things are bound to happen, this culture under-

stands that there is a definite sequence of causes and effects thatultimately lead to each and every failure. In the culture that is usedas a basis for comparison, the members of the organization arewilling and able to use their understanding of the sequence ofevents leading to failures to intervene before failures occur, or torespond in a manner that absolutely minimizes their impact.Although the author has experienced all the elements that aredescribed in this book in one organization or another, none of those

organizations has succeeded in putting all the pieces together intoa comprehensive system that will apply all the concepts to thefullest extent possible. The accomplishment of that objective would

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be the result of the Failure Mapping environment described herein.The author has also taken the liberty of tightening up some

concepts that he feels have long been too loosely defined, to thedetriment of the structures and discipline needed to accomplish theorganizational and cultural objectives described above. Forinstance, the concepts of diagnostics and troubleshooting are twofunctions that are frequently only loosely defined and, as a resultthey are frequently accomplished by a range of individuals in a vari-ety of roles with little structure and in a hit-or-miss fashion. Thisbook focuses on those two roles as keys to being able to quicklyrespond to failures and to apply the proper solution(s). Other exam-ples of poor definitions are those for terms like Malfunction Reportand Failure Mode. In this context, those two terms represent thespecific starting points (Affected Function – Current Behavior), andending point (Defective Component – Component Condition), forthe portion of the Failure Map that is used to support immediateresponse to failures.

As with several other books in this series, the author haswritten the current book in a manner that makes it a useful tool forthe reliability professional and other individuals who depend on reli-ability for their success, and the successful use of assets andorganizations that they manage. The book is short enough to beused by busy people, but it provides sufficient detail to completelydescribe the subject being addressed.

For those readers who are not familiar with the concept of

Failure Mapping and how it is applied, a brief summary is includedin the appendix. It is hoped that readers will enjoy this book andfind its contents useful to them and their organizations.

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Failure Mapping

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