1. RCM Theory and Concepts Workshop Module 1 – Introduction
Continuously Pushing the Limits of Innovation, Technology & Conventional Thinking
RCM Theory and Concepts Workshop
Module 1 – Introduction

2. Agenda RCM Introduction and Definition History Policy
RCM Process Overview

3. RCM Introduction Reliability-Centered Maintenance (RCM)
An analytical process used to determine appropriate failure management strategies to ensure safe and cost-effective operations of a physical asset in a specific operating environment.
Failure Management strategies
Preventive Maintenance (PM) requirements
Other actions
Run to failure (No PM)
Helps the maintainer do the right maintenance at the right time.

4. RCM Introduction Goal of RCM Avoid or reduce failure CONSEQUENCES
Not necessarily to avoid failures
Failure Consequences are the effects of failure on:
Personal and Equipment Safety
Environmental Health/Compliance
Operations
Economics

5. RCM Defined
RCM develops logical failure management strategies based on the following precepts:
The objective of maintenance is to preserve an item’s function(s).
RCM seeks to manage the consequences of failure – not to prevent all failures.
RCM is driven first by safety. When safety is not an issue, maintenance must be justified on the ability to complete the mission and finally, on economic grounds.
RCM acknowledges that at best, maintenance can only sustain the system to its inherent level of reliability within the operating context.
RCM uses design, operations, maintenance, logistics, and cost data, to improve operating capability, design and maintenance.
RCM is a continuous process that requires sustainment throughout the life cycle.

6. RCM Defined
Currently there are many processes that call themselves RCM
SAE JA1011 provides criteria to distinguish processes that follow the original tenets of RCM
This workshop is based on the RCM methodology defined in SAE JA1011. Today the
US Army performs RCM in
accordance with SAE JA1011.

7. RCM Defined
Overview and Notes
SAE JA1011 “Evaluation Criteria for RCM Processes” defines seven questions for RCM:
What are the functions…of the asset…(functions)?
In what ways can it fail…(functional failures)?
What causes each functional failure (failure modes)?
What happens when each failure occurs (failure effects)?
In what way does each failure matter (failure consequences)?
What should be done…(proactive tasks and intervals)?
What should be done if a suitable proactive task cannot be found?

8. History of RCM HOW DID RCM COME ABOUT?
Early PM Programs were based on the concept that periodic overhauls ensured reliability and, therefore, safety.
Aircraft overhauls were often massive teardown and rebuild efforts with the expectation that failures would be prevented due to these events.

9. History of RCM HOW DID RCM COME ABOUT?
In 1960’s, Commercial airlines questioned value of overhauls
Rising costs, without more reliability
747 would have required millions of man-hours under previous maintenance philosophy
FAA and airlines established “Maintenance Steering Group (MSG)” to investigate new approaches
MSG logic developed and first applied to Boeing 747
1978 DoD commissioned United Airlines to develop maintenance analysis process
Stan Nowlan and Howard Heep Report coined “RCM” term

10. Unit I Module 1 - Introduction to RCM
History of RCM
Conditional Probability
of Failure
Time
Overhaul interval
OVERHAUL PHILOSOPHY
ASSUMES THIS
IS TRUE……
What the airlines discovered
Statistical analysis showed, in most cases, no change in safety or reliability when overhaul limits changed.
Initial overhaul limits were not analytically based.
High repair costs for little or no benefits.
Facts about overhauls
Many failure modes do not support overhaul philosophy- have no ‘right’ overhaul time.
Lose considerable component life.
Overhauls re-introduce infant mortality failures.
Previous maintenance philosophies were based on the assumption that the bathtub curve described the failure characteristics of most equipment.
Describe bathtub curve (infant mortality, low failure rate, wear out)
The airline study found:
Changing overhaul limits had little or no effect on reliability and safety.
There was No analytical basis for overhaul philosophy.
Airlines weren’t getting what they thought they were getting for the money they were spending.
Further investigation revealed most failure modes don’t fit the “bathtub curve” and the overhaul strategy. Also, that forcing components into periodic overhauls, lost useful component life and reintroduced the possibility of early failures.
Many Failure modes do not support overhaul philosophy.
Component life can actually decrease with maintenance.
Can actually re-introduce infant mortality rate which disappears over the life of the component.

11. Unit I Module 1 - Introduction to RCM
History of RCM
WEAR OUT CURVES
Wear Out curves with potential benefit from overhaul
UAL Broberg MSP
4% 3% 3%
2% 1% 17%
5% 4% 3%
7% 11% 6%
14% 15% 42%
68% 66% 29%
Wear Out curves without potential benefit from overhaul
Ranges from 8% to 23%
Wear out analysis from 3 studies revealed some eye-opening outcomes: (CD in back of Guide has more information on studies)
Groups of Components have different wear out curves
Limiting operating age benefits reliability for 8% to 23% of components (top three curves)
Overhaul (limiting operating age) could be detrimental in up to 72% of components—due to reintroduction of ‘infant mortality”. Point out very top and bottom distribution
There is no age related wear out on a majority (77% to 92%) of components and failures tend to be random. Therefore, no benefit from a scheduled overhaul.
These 3 studies related to 3 specific equipment types, similar results are expected for other equipment.
Ranges from 77% to 92%

12. NAVAIR Design Interface/Maintenance Planning (DI/MP) Training Course
RCM History
NAVAIR Design Interface/Maintenance Planning (DI/MP) Training Course
Alternatives to Overhaul based maintenance
Inspections
Look for “potential failure” condition
Leaves item in-service for more of its useful life
“Fly to failure”
When consequences are severe - not an option
When consequences are acceptable - “fly to failure” may be best approach for cost/mission
RCM applies the most appropriate maintenance philosophy to each failure mode based on available data
Unit 1: Introduction to Design Interface/Maintenance Planning

13. Foundation of Modern Day RCM Processes
History of RCM
1965: Studies show scheduled overhaul of complex equipment has little or no effect on in-service reliability
: Airline and manufactures form Maintenance Steering Group (MSG) and produce MSG 1, “ Handbook: Maintenance Evaluation and Program Development.” First applied to Boeing 747
1970: MSG handbook updated to MSG-2, “Airline/ Manufactures Maintenance Program Planning Document”. Applied to L-1011 and DC-10
1972: MSG-2 techniques applied to NAVAIR systems (P-3A, S-3A, and F-4J)
1975: NAVAIR applied Analytical Maintenance Program to Naval aircraft and engine programs, using MSG-2 type logic (NAVAIR )
The evolution of RCM is as follows: (refer to the slide)
Of particular note is that NAVAIR became involved in the RCM development quite early (1972) and has maintained a leadership role ever since.
Key developments in the overall progression of RCM was the watershed event in the publishing of the “Nowlan and Heap” report in This report become the point of departure for virtually all RCM processes developed since, and the major source for RCM processes applied to non-aerospace industries.
1978: Department of Defense (DOD) sponsored DOD report AD-A066579, “Reliability Centered Maintenance” by Nowlan and Heap - Updates MSG-2 approach with better guidance on process and interval determination
Foundation of Modern Day RCM Processes

14. History of RCM
1980: Army issued Army Pamphlet 750–40, “Guide to RCM for Fielded Equipment ”
1981: DOD issued MIL-HDBK-266, “Application of RCM to Naval Aircraft, Weapon Systems and Support Equipment” to implement RCM concepts from N&H Report
1983: MSG-3 issued. Used in design of Boeing 757 and 767 aircraft. Added emphasis on structural inspection programs. Similar to RCM, but lacked guidance on interval determination
1985: US Air Force (USAF) issued MIL-STD-1843, " RCM Requirements for Aircraft, Engines and Equipment“ - Similar to MSG-3 (Cancelled without replacement in 1995, USAF Instructions contain current policy/guidance)
1986: NAVAIR issued MIL-STD-2173, "RCM Requirements for Naval Aircraft, Weapons Systems and Support Equipment". Superseded MIL-HDBK-266 & NAVAIR
Also in 1986 NAVAIR issued to provide Age Exploration guidance

15. History of RCM
1992: Coast Guard issued CGTO PG–85–00–30, “Aeronautical Engineering Process Guide for RCM Process”
Mid 1990’s DOD directs replacement of Military Standards with commercial standards. DOD asks SAE to develop “commercial” RCM standard
1996: NAVAIR updated NAVAIR to contain complete RCM process due to cancellation of MIL-STDs
Also in the 1990’s: Nuclear Power industry adopts approach due to focus on avoiding “safety consequences” while reducing costs
As the RCM process evolved, Mil-specs for the Navy and Air Force were issues along with various guides for other services. Note also, the initial issue of the NAVAIR was to provide Age Exploration guidance only.
MSG-3 was also issued providing guidance for airlines and the FAA. MSG-3 is still used today, although it has been updated several times since its original issue. In addition to airlines, it is being adopted by general aviation, and an international RCM standard has been developed which replicates most of its provisions.
1999: SOCIETY OF AUTOMOTIVE ENGINEERS (SAE) issued SAE JA1011, “Evaluation Criteria for RCM Processes”

16. Unit I Module 1 - Introduction to RCM
History of RCM
Also in the 1990’s:
“RCM II” by John Moubray published in UK in 1990
“Reliability-Centered Maintenance” by Mac Smith published in US in 1993
As interest in RCM increased, Others introduced a variety of processes that they called “RCM”
In the 2000’s:
2001: NAVAIR updated to capture improvements developed during SAE JA1011 work
2002: SAE issued SAE JA1012, “A Guide to the RCM Standard” - amplifies and clarifies key concepts and terms from SAE JA1011
200X:DOD Instructions- CBM Standards
200X - Current: DOD RCM WIPT effort to collaborate on RCM practices between services
Add RCM /CBM delink from CBM,
As RCM processes were evolving in the military and airline community, other industries were taking notice. Initially, the Nuclear Power industry adopted RCM due to its focus on ensuring safety and the discipline and audit trails it provided, while reducing unnecessary maintenance.
Later, John Moubray, a industrial maintenance engineer, became aware of RCM and investigated its value in a wider industrial concept, going back to the Nowlan and Heap roots, and publishing the book (essentially a textbook) “RCM II” in It is still considered one of the best single sources for understanding RCM today.
Another leader in the broader application of RCM was Mac Smith, who published a similar guide book and process in 1993.
As RCM applications became more widespread, so did “copycat” processes that deviated from the basic tenets of the Nowlan and Heap philosophy, but adopted the name. Moubray and others became so concerned about the confusion caused by RCM processes that barely resembled the originating philosophy, that they became engaged with the SAE in the development of an industry standard. Originally intending to develop a singular RCM process, it became clear that enough acceptable deviation existed in valid RCM approaches, that the SAE JA1011 focus was reoriented to a set of criteria that could be used to identify “valid” RCM approaches. SAE JA1012 was then developed to more fully describe acceptable approaches without endorsing a particular one. NAVAIR provided the most consistent representation and input into the development of these standards, and adopted JA1011 as the commercial replacement to MIL-STD-2173 upon its issue.

17. Unit I Module 1 - Introduction to RCM
RCM Process Overview
There are 4 basic elements of an RCM Program:
1. Planning and Preparation
2. RCM Analysis
3. Implementation of Results
4. Sustaining the Analysis
This module will present a high level overview of these four basic elements.
Planning and Preparation
Initial RCM Analysis
Implementation of Results
Sustaining the Analysis

18. PLANNING AND PREPARATION
RCM Process Overview
Data
1. Emergent Issues
2. Age Exploration
3. Hardware Changes
4. Trend/degrader analysis
5. Document Reviews
1. Package Maintenance Task
2. Implement Onetime Tasks
1. Identify Team and responsibilities Identify and document Review Process
2. Identify analysis items Orientation/Training
3. Prioritize Items Ground Rules and Assumptions
8. Failure Consequences
9. Task Evaluation
10. Task Selection
4. Function
5. Functional Failure
6. Failure Mode
7. Failure Effects
1. Equipment Kick-off Meeting
2. Initial Data Gathering
3. Hardware Partition
FMECA
SUSTAIN
Maintenance
Program
IMPLEMENT RESULTS
Requirements
ANALYSIS
Analysis Approach RCM Plan
PLANNING AND PREPARATION

19. Unit I Module 1 - Introduction to RCM
RCM Process
Planning and Preparation
Identifies and resolves issues that must be addressed prior to beginning an analysis.
Answers the following:
Who
What
In what order
How
With what resources
When
Any barrier or issue that requires resolution prior to commencing RCM should be addressed up front.
Planning and Preparation is intended to identify who does what, in what order, with what process, with what resources, in what timeframe.
We will look at Planning and Preparation in more detail in the next module.

20. Unit I Module 1 - Introduction to RCM
RCM Process
RCM Analysis
Once an asset has been selected for analysis and the proper groundwork has been accomplished, the analysis phase begins.
Analysis Steps:
Equipment Kick-off Meeting
Initial Data gathering
Hardware Partitioning
FMECA
Failure Consequences
Task Evaluation
Task Selection
Once an asset has been selected for analysis and the proper groundwork has been accomplished, the analysis phase begins.
The analysis phase contains the following steps:
Equipment Kick-off Meeting
Initial Data gathering
Hardware Partitioning
FMECA
Failure Consequences
Task Evaluation
Task Selection
We’ll discuss most of these steps in greater detail in subsequent modules.

21. RCM Process Implementation
When complete, the RCM analysis provides a list of maintenance tasks and recommendations.
In order to realize the benefits of these recommendations, they need to be incorporated into a coherent and efficient maintenance program.
“Packaging” is the process of combining discrete maintenance recommendations into a maintenance program.
A completed analysis provides a list of tasks and recommendations.
Tasks and recommendations mean little if they are not incorporated into a comprehensive Maintenance Program.
“Packaging” is the process of combining discrete maintenance recommendations into a maintenance program.
Examples of this are groupings of maintenance tasks into special inspections and phase maintenance packages on aircraft.
Packaging tasks can bring efficiency to the maintenance program saving time and cost.

22. RCM Process Sustainment
As with many other processes, a large part of the benefit of RCM may be realized over time through a process of formal monitoring and continuous improvement…
Initial analysis may need update over time:
Incorrect assumptions on initial analysis
Hardware changes
Unexpected failures
Operating environment changes
Other emergent issues
To realize the maximum benefit, a process of monitoring and continuous process improvement must be employed. RCM sustainment is the continuous improvement vehicle for the maintenance program.
Sustainment is the “living” part of the process.
Benefit from initial analysis may be sub-optimized if the analysis is not “refreshed” throughout the life-cycle of the equipment.
Key point: A program must plan ahead to provide the resources necessary to benefit from a successful RCM Program. Management must “buy-in” to the process up-front, and stand behind the decision, to continuously up-date the product. Significant ROI normally can not be achieved without a continuous process.

23. Module Summary RCM Introduction and Definition History Policy
RCM Process Overview
Next Module…RCM Process

24. Questions ?

25. Backup Slides

26. Hazard Risk Matrix Example:
FREQUENCY
SEVERITY
FREQUENT
> 1 per 1,000
Hours
PROBABLE
> 1 per 10,000
OCCASIONAL
> 1 per 100,000
REMOTE
> 1 per 1,000,000
IMPROBABLE
< 1 per 1,000,000
CATASTROPHIC (I)
CRITICAL (II)
MARGINAL (III)
MINOR (IV)
Death or Severe Injury
Significant Environmental Impact
Damage > $1M
Loss of availability > 1 week
Minor Injury
Damage >$100K and < $1M
Loss of availability > 24 hrs and < 7 days
Damage >$10K and < $100K
Loss of availability > 4 hrs
and < 24 hrs
Damage <$10K
Loss of availability < 4 hrs 1
HIGH 3 4 2 5 8
MED 6 7 9 10
LOW 12
ACCEPT 13 15 16 17 20 19 14 11 18

27. FMECA FMECA: Failure Mode, Effects, and Criticality Analysis
Process used to identify, document, and rank the importance of potential failure modes for a system or piece of equipment:
Steps involve identifying...
Functions – what it does for you
Functional Failures – how it fails to do it
Failure Modes – why it fails to do it
Failure Effects – what happens
Severity of Failure – How bad it is
Failure Frequency – How often it happens
Failure Detection – How failures are identified
The process of performing a FMECA is by itself, not a complex one. It must however, be given the appropriate rigor in order to ensure that all potential Failure Modes are identified and addressed in the analysis. Failure to do so may leave the flightline maintainer without the proper resources to properly maintain the aircraft.