The business case for RCM implementation for the majority of existing facilities where the inventory is stable is primarily based on the following cost avoidance techniques:
- Reduction in time based maintenance hours
- Reduced catastrophic failures and resultant costs
- Age Exploration - OEM recommendations for example
For organizations where new construction and major revitalization are occurring, the business case also includes using the following to identify, implement, and verify (quantification) reliability issues:
- Failure Modes and Effects Analysis
- Operations and Maintenance tasks
- Initial tools and training
- Age Exploration for revitalization
Note: This paper does not address the basics of RCM and is intended as an aid to deciding the applicability and portion of RCM to apply to your facility and operating environment.
Where to Start:
- Determine if there is any reason to change the way you do business
While RCM, is the paraphrase others, the only truly logical and empirical approach for establishing and maintaining a maintenance program it is not for everyone and should not be pursued unless there is a factual basis which offers either tangible or intangible benefits. These benefits include only the following:
- Reliability issues in - terms of safety, security, and mission
- Financial return both, direct and lost opportunity costs
Building the business case and implementation strategy should be based on both strategic (global) and tactical (event) key performance indicators regardless of the type of facility being considered.
Choosing the Appropriate RCM Approach
There are several ways to conduct and implement an RCM program. The program can be based on rigorous Failure Modes and Effects Analysis (FMEA), complete with mathematically-calculated probabilities of failure based on design and/or historical data, intuition or common-sense, and/or experimental data and modeling. These approaches may be called Classical, Rigorous, Intuitive, Streamlined, or Abbreviated. Other terms sometimes used for these same approaches include Concise, Preventive Maintenance (PM) Optimization, Reliability Based, and Reliability Enhanced. All are applicable. The decision of what technique to use should be left to the end user and be based on:
- Consequences of failure
- Probability of failure
- Historical data available
- Risk tolerance
Classical or rigorous RCM provides the most knowledge and data concerning system functions, failure modes, and maintenance actions addressing functional failures of any of the RCM approaches. Rigorous RCM analysis is the method first proposed and documented by Nowlan and Heap and later modified by John Moubray, Anthony M. Smith, and others. In addition, this method should produce the most complete documentation of all the methods addressed here.
Classical or rigorous RCM historically has been based primarily on the FMEA with little, if any, analysis of historical performance data. In addition, rigorous RCM analysis is extremely labor intensive and often postpones the implementation of obvious condition monitoring tasks.
The classical approach should be limited to the following three situations:
- The consequences of failure result in catastrophic risk in terms of environment, health, or safety and/or complete economic failure of the business unit.
- The resultant reliability and associated maintenance cost is still unacceptable after performing and implementing a streamlined type FMEA.
- The system/equipment is new to the organization and insufficient corporate maintenance and operational knowledge exists on its function and functional failures.
The intuitive approach identifies and implements the obvious, usually condition-based, tasks with minimal analysis. In addition, it culls or eliminates low value maintenance tasks based on historical data and Maintenance and Operations (M&O) personnel input. The intent is to minimize the initial analysis time in order to realize early-wins that help offset the cost of the FMEA and condition monitoring capabilities development.
Reliance on historical records and personnel knowledge can introduce errors into the process that may lead to missing hidden failures where a low probability of occurrence exists. In addition, the intuitive process requires that at least one individual has a thorough understanding of the various condition monitoring technologies and failure mechanisms.
The streamlined approach should be utilized when:
- The function of the system/equipment is well understood.
- Functional failure of the system/equipment will not result in loss of life or catastrophic impact on the environment or unit business.
For these reasons, the streamlined or intuitive approach is recommended for the majority of facilities. Exceptions are where single points of failure exist and the associated risk of failure cannot be mitigated.
The streamlined or intuitive approach is recommended due to the high analysis cost of the rigorous approach, the relative low impact of failure of most facilities systems, the type of systems and components maintained, and the amount of redundant systems in place. The streamlined approach uses the same principles as the rigorous, but recognizes not all failure modes will be analyzed. RCM users have reviewed the various processes in use and have determined that the most economical and efficient approach is to use a combination of rigorous (formal) and intuitive analysis depending on system criticality and failure impact.
A more rigorous analysis may be warranted for those systems and components where the streamlined or intuitive RCM process has been used and the resultant reliability is still unacceptable in terms of security, safety, cost, or mission impact.
Three Approaches to RCM
1. Globally Dispersed - Large New Construction Effort
a. Use of generic FMEA data to construct maintenance program tasks, interval, and training programs
b. Commissioning developed using FMEA with a concentration on identifying and addressing single points of failure
c. Criticality and probability of failure used to determine stocking plan
d. Roving condition monitoring teams to determine priority and scheduling of repair and PM teams
e. Root cause failure centrally located and coordinated by system experts
f. Metrics developed to track availability, mean time between failure, and costs
g. Significant overhaul of design and procurement process to implement RCM
h. Process reengineering used to identify potential opportunities
2. Dispersed - Aging and Diminishing Inventory
a. No FMEA performed on standard facility equipment where sufficient redundancy existed. FMEA performed on a case - by -case basis for critical program equipment
b. Immediate implementation of condition monitoring technologies appropriate to machinery type and mission
c. Dispersed technologists at each location
d. Minimum central management
e. Virtual teams to shard information
f. Commissioning limited to condition monitoring acceptance testing
g. Metrics developed to track availability, mean time between failure, and costs
h. Limited changes to building specifications
3. Centrally Located (for the most part) - Limited Revitalization
a. Generic FMEA used and all maintenance tasks revised
b. RCM added to position descriptions and annual performance plans
c. Spare parts switched to Just - In - Time
d. Dispersed first line maintenance with centralized technologists
e. Immediate implementation of condition monitoring technologies appropriate to machinery type and mission
f. Limited use of acceptance testing
g. Metrics developed to track availability, mean time between failure, and costs and reported to all levels of the organization on a monthly basis
h. On -going training program implemented - 40 hours per employee per year
In closing, there are these basic rules:
- Pick the appropriate level of sophistication based on a business plan which addresses implementation cost, time required, return - on investment, and risk mitigation
- Create and apply the appropriate Key Performance Indicators and make them public
- Communicate and train everyone
- Be shameless in promoting your program - crow about your successes and acknowledge your failures in order to build and maintain credibility
- Do not over analyze
- Stay the course, RCM is not a program of the quarter
- Design and use your management software to analyze and identify areas problems
- Do not simply add a condition monitoring technology without understanding related changes
Article submitted by Alan K. Pride, Associate Director, Smithsonian Institute