What is Reliability Centered Maintenance?
RCM programs can include preventive maintenance, predictive maintenance, real-time monitoring, reactive maintenance and proactive maintenance tactics for each piece of equipment. The idea is to create the ideal combination of the above-mentioned tactics to maximize the availability and performance of any given asset at the lowest life-cycle cost.
The technical standard SAE JA1011, Evaluation Criteria for RCM Processes by the Society of Automotive Engineers, identifies the minimum criteria a process must meet in order to be classified as RCM. It begins with the following seven questions for each asset:
- What is the item supposed to do and its associated performance standards?
- In what ways can it fail to provide the required functions?
- What are the events that cause each failure?
- What happens when each failure occurs?
- In what way does each failure matter?
- What systematic task can be performed proactively to prevent, or to diminish to a satisfactory degree, the consequences of the failure?
- What must be done if a suitable preventive task cannot be found?
To set up a reliability centered maintenance program, you should develop a plan (in writing) that incorporates goals, scheduling, and internal and external resources. Your RCM team may include professionals from numerous fields of expertise including mechanical maintenance, electrical, process control, operations and design. You should also get buy-in from upper management, who should be able to grasp the overall value of a reliability centered maintenance program.
Development of a reliability centered maintenance (RCM) program includes the following steps:
In order to allow maintenance reliability resources to focus on the most critical maintenance situations, you should classify according to Relative Importance of Maintenance Expenditure (RIME) Priority. RIME utilizes two rating scales, asset criticality and procedure criticality, and work is prioritized by multiplying the two together.
Asset criticality is determined by input gathered from each department’s management and analyzed to set priority based on consequence and likelihood of failure. From there, work categories are developed and procedure priorities are set based on factors such as severity of the consequence of a failure, safety, environmental impact, regulatory compliance, financial loss, expensive or time consuming repairs, and possible collateral damage.
Establish Downtime Requirements
Downtime represents the number of hours an asset is not available for use during its normal operating time frame. It should be calculated from the time of failure to the time it’s restored to operation. Downtime does not apply to preventive maintenance unless additional repairs are required outside the scope of the planned repair. Non-scheduled downtime should be required tracking on all work orders.
Develop Failure and Asset Condition Tracking Criteria
Data gathered while completing preventive maintenance repairs, as well as data recorded on work orders, should be used to develop failure and asset condition tracking codes. Asset criticality, consequences of failure and ability to gather data all come into play when developing asset condition tracking codes. These will be utilized to trend critical parameters, which will predict failures before they occur. Asset operating conditions can be tracked by user-defined fields or codes. Codes can also be used to automatically generate a work request when a parameter is out of a specification.
Determine Spare Parts Requirements
Each asset should be reviewed to determine if the part should be carried on-site as well as the proper stocking and reordering points for those particular parts. To determine this, review parts usage history for the equipment and utilize a decision matrix or ranking system. Examples of spare parts decision questions are:
- Does it support critical equipment?
- Is it a high-usage part?
- Has it had a high number of stock-outs?
- Is the part readily available locally?
- Does the part have a long lead time when ordering?
- Is it a high-cost part?
From here, develop a set of codes to determine inventory count intervals in addition to a set of codes to determine stocking level review.
Create Standard Operating Procedures
Develop Standard Operating Procedures for a computerized maintenance management system (CMMS). Properly implemented CMMS software ensures the collection of complete and accurate data for each asset. It’s important to provide CMMS training for all applicable employees so that data is entered correctly and consistently.
Establish Review Schedules
Performing scheduled asset reviews will help to quickly identify red flags like excessive downtime, high number of failures, common failures and disproportionate parts usage. From there, action items can be determined. It may be deemed necessary to fine-tune preventive maintenance such as higher frequency, lower frequency or task adjustment (although all minimum requirements of the manufacturer’s recommended preventive maintenance procedures should be adhered to until the equipment warranty has expired).
An in-depth asset review should include work order history, downtime, parts usage, failure and condition information, trending data, manufacturer’s technical information and specific key performance indicators such as mean time between failure. The review schedule should be determined by equipment criticality and results will determine: current criticality to the production plant, parts adjustments, overhaul and refurbishment requirements as well as decommissioning requirements. An RCM program is an ongoing process resulting from one part of the system forcing reconsideration and adjustments in other parts of the system.
CMMS software gives organizations the ability to document each asset’s work history, failures, costs and other information that can be used to analyze trends and develop goals. It provides the tools necessary to determine a proper maintenance regimen for each critical asset—the embodiment of a successful reliability centered maintenance program. Maintenance managers utilizing a CMMS to employ a reliability centered maintenance program have the utmost advantage when it comes to achieving maximum reliability, performance and safety of equipment.
Read More on Maintenance Strategy
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