core principles of rcm compatibility mode

CORE Principles of Reliability-Centered MaintenanceCentered Maintenance

Rich Overman CMRPRich Overman, CMRP(904) 655-0787 Cell

[email protected]

© 2012 CORE Principles, LLC, all rights reserved 1

IntroductionL t 1970’ h d i f t• Late 1970’s ushered in a new era of asset maintenance

• United States Department of Defense published the seminal book entitled Reliability-Centered Maintenance (RCM)

• Entire industries have grown from this one gbook

• Growth brings variability© 2012 CORE Principles, LLC, all rights reserved 2

Growth brings variability

Definition of RCM• “a logical discipline for the development of

scheduled maintenance programs.” – Nolan and p gHeap

• “Reliability-centered Maintenance: a process used toReliability centered Maintenance: a process used to determine what must be done to ensure that any physical asset continues to do what its users wantedphysical asset continues to do what its users wanted it to do in its present operating context.” – John MoubrayMoubray


Definitions of RCM• RCM is “the best way to develop a maintenance

improvement program ” A M Smithimprovement program. – A.M. Smith• “RCM uses a cross-functional team to develop a

l t i t t t d i d tcomplete maintenance strategy designed to ensure inherent design reliability for a process or piece of

i t ” D Pl k ttequipment.” – Doug Plucknett• RCM “is to identify components whose functional

failures can cause unwanted consequences to ones plant or facility.” – Neil Bloom

© 2012CORE Principles, LLC, all rights reserved 4

Process Variants

• Jack Nicholas categorized various RCM processes:p– Classical– VariantsVariants– Derivatives

• Result is RCM has come to mean different• Result is RCM has come to mean different things to different people


CORE Principles of RCM

• Not presenting:– RCM processRCM process– RCM philosophy

• Primary or CORE Principles of RCM• Primary or CORE Principles of RCM• Underlying principles upon which all RCM

b dprocesses are based.


Core Principles of RCM

• Components Fail• Operational ImpactOperational Impact• Reliability Engineering Solutions


Components Fail• Without intervention everything will eventually fail• Each component has failure characteristicEach component has failure characteristic • Nolan and Heap identified six failure characteristics


Components Fail• Failure characteristic curves basis for all of

the RCM processesthe RCM processes• One fundamental principle of RCM is

identification of component failureidentification of component failure characteristicTh l i t tt t t d t d f il• The goal is to attempt to understand failure characteristic to identify appropriate i t tiintervention


Failure Characteristics


But There is MoreBut There is More• It is intuitively obvious that components will fail• It is possible to intervene in some way to try to

prevent all failuresp• It is equally intuitively obvious that no company can

afford to try to prevent all failuresafford to try to prevent all failures• The primary purpose of RCM is to identify the

appropriate interventionappropriate intervention• Simply recognizing that components fail is not

ffi i tsufficient© 2012 CORE Principles, LLC, all rights reserved 11

Operational Impact• Every component failure has some degree of

operational impact• Direct operational impact ranges from shutting

down to none• Indirect operational impact is to drain resources• Every failure requires resources that could be more• Every failure requires resources that could be more

efficiently and effectively used to increase company valuevalue


Operational Impact

• Goal of RCM– evaluateevaluate– categorize– PrioritizePrioritize– understand the operational impact of failure

• Identify the appropriate intervention• Identify the appropriate intervention.


But There is More

• Components fail• They impact operationsThey impact operations• That knowledge, by itself, is not sufficient

to identify appropriate interventionto identify appropriate intervention• Need a logical way of organizing and

l i i f i k devaluating information to make sound intervention decisions


Reliability Engineering Solutions

• Reliability Engineers used analytical techniques for yearsq y– Failure Modes, Effects, and Criticality Analysis

(FMECA)( )– Stochastic analyses

• Only logical to apply these techniques to theOnly logical to apply these techniques to the issue of failure intervention.


FMECA• FMECA provides logical method for identifying

failures and evaluating operational impact• Every component failure leads to loss of a function• Loss of function has process effectoss o u ct o as p ocess e ect• FMECA process identifies and documents

Functions– Functions– Functional failures

F il d– Failure modes– Effects of failure at various levels

C i i li l i i / i i i i f il d– Criticality analysis categorizes/prioritizing failure modes© 2012 CORE Principles, LLC, all rights reserved 18

FMECA

• Importance of FMECA to RCM process cannot be overstated

• Understanding operational impact of failure is crucial to developing appropriate interventioncrucial to developing appropriate intervention

• “a good FMECA will not guarantee a good RCM analysis but a bad FMECA will guarantee a badanalysis but a bad FMECA will guarantee a bad RCM analysis.”


Stochastic Analysis• FMECA is great existing Reliability Engineering

tool for understanding operational impact of failures• Not sufficient for developing intervention schemes• FMECA is foundation but not end of RCM processC s ou dat o but ot e d o C p ocess• Stochastic analysis is other Reliability Engineering

tool that needs to be employedtool that needs to be employed• Most common stochastic analysis used in RCM is

Weib l anal sisWeibul analysis• Weibul analysis can identify failure characteristic

li bl f il dcurve applicable to failure mode© 2012 CORE Principles, LLC, all rights reserved 20

Relating Failure to Intervention• Failure characteristic defines intervention• Scheduled overhaul/replacement would not work for

infant mortality characteristic• A random failure characteristic is more appropriate a do a u e c a acte st c s o e app op ate

for applying a predictive maintenance• A wear out characteristic would benefit from either• A wear out characteristic would benefit from either

a predictive maintenance or overhaul/replacement interventionintervention

• Stochastic techniques provide information to determine intervention intervaldetermine intervention interval


Function Preservation

How do I keep fl id fl ifluid flowing out

of tank?Classical RCM asks:A

Traditional analysis asks: BHow do I keep the pump operating?p p p g

22© 2012 CORE Principles, LLC, all rights reserved

Function Preservation

How do I keep fl id fl i

What are ways to keep fluid flowing out of fluid flowing out

of tank?A fluid flowing out of Tank B other than keeping the pump

i ?

Brunning?

• Bypass valve• Standby pumpStandby pump• Keep tank B full enough to give time to change a failed pump• With a functional approach many alternatives are available


7 Steps in the RCM Process1. System Selection

2. Systems Boundary Definitions

3. System Description3. System Description

4. Identify System Functions &Functional Failures

5. Failure Modes and Effects Analysis (FMEA)

6 k S l i6. Task Selection

7. Program Implementation7. Program Implementation

Source: William A. Keeter, MQS and Jack Nicholas 24© 2012 CORE Principles, LLC, all rights reserved

SAE Standard1. What are the functions, performance standards in the

present operating context? (Function)present operating context? (Function)2. In what ways does it fail to fulfill its functions? (Functional

failure))3. What causes each functional failure? (Failure mode)4. What happens when each failure occurs? (Failure effects)4. What happens when each failure occurs? (Failure effects)5. Why does the failure matter (Failure consequences)6 What can be done to predict or prevent each failure?6. What can be done to predict or prevent each failure?7. What should be done if a suitable task cannot be found?


Example Analysis – Water Jet Machine

• Nagging Failures – Worn and failed tips

• Lots of down time

• Cause – “Dirty” Water

• Source Versatile Reliability Centered• Source – Versatile Reliability-Centered

Maintenance


System and Boundaries


Water Jet Reclamation System


Water Jet RCM Analysis• 7 Functions

14 F ti l F il• 14 Functional Failures• 47 Failure Modes• 8 Inspections• 4 Overhaul/discard4 Overhaul/discard• 1 Failure finding

25 R t f il• 25 Run-to-failure• Estimated annual savings $334K


Conclusion

• All RCM processes apply CORE Principles of RCMAll RCM processes apply CORE Principles of RCM

• Must be applied to identify appropriate failure

intervention

• Component failure must be understood

• Operational impact assessed

• Reliability Engineering tools applied• Reliability Engineering tools applied© 2012 CORE Principles, LLC, all rights reserved 32

Conclusion• Each RCM process available today applies the CORE

Principles of RCM to varying degree• Degree applied is indicative of overall benefit• If CORE Principles of RCM applied superficially - some

but limited benefit• More rigorous application of the CORE Principles of RCM

- enhanced benefits• Degree to which CORE Principles of RCM are applied

ff f l iaffects cost of analysis• The more a company is willing to invest in RCM the more

b fit th tbenefit they can expect© 2012 CORE Principles, LLC, all rights reserved 33

core principles of rcm compatibility mode

Documents

definitions of rcm rcm

core principles of rcm

core principles of reliability

rcm processesthe rcm

variabilitydefinition

smith rcm

various rcm processes

i t tt t t d t d f il