Due to the complexity of present-day manufacturing processes and equipment, companies are unable to predict when important assets are likely to wear out, and consequently, unable to replace them before they fail. This is because it’s not the entire piece of equipment that fails, but rather small pieces within the equipment that are failing at a random distribution. This is where reliability-centered maintenance comes in. Here are five important components to know about RCM.
To determine the maintenance approach for a piece of equipment, the purpose, or function, of that equipment first must be determined. Every piece of equipment has at least one main primary function and may have other secondary functions; however, the primary function is the one that has to be clearly stated in order to move forward. Once the primary function is understood, the expected output can be quantified. This is imperative because without knowing what, how often, and how many of something the equipment is supposed to be producing, it will be impossible to know if the asset is properly functioning or not.
Now that the expected output has been quantified, a total or partial functional failure can be determined. Total functional failure happens when the entire asset stops working, and partial functional failure happens when the asset is still working, but not performing the way it should.
Failure modes determine the events that led to functional failure. To analyze failure modes, consider these three things:
- The most common reasons for a machine’s performance to drop include dirt, lack of lubrication, disassembling of components, deteriorating parts, and human error.
- Increasing the output to be more than what was originally required of the machine can lead to wear and tear and eventual failure.
- Finding that the machine has never been capable of delivering the expected output can be the result of an insufficient design or a mistake in quantifying the output to begin with.
In total, between one and thirty failure modes can be expected for every one functional failure.
To determine what happened in the equipment at the time of the failure, it’s important to take note of the effects that the failure had on the machine, including:
- Physical evidence indicating that a failure occurred
- Negative impact on the environment and people’s health and safety
- Negative impact on operations
- Damages to the equipment, facility, or product
- What it will take to fix the asset
Now that the failure effects have been determined, the overall failure consequences can be analyzed. In other words, a qualitative evaluation must be performed to understand what functional failure means for the company. The way this is done will be determined by the type of functional failures we are analyzing. If they are hidden, the analysis becomes more complicated and requires careful consideration of the protective and protected devices and their probability of failure. If they are evident, the equipment’s functional failure can be analyzed by the operator. By weighing the potential danger of the failure, the costs, and the consequences, the operator can determine the failure’s degree of importance and need for repair.
These are five important components used to determine an asset’s maintenance strategy, otherwise known as Failure Mode and Effect Analysis (FMEA). The purpose of RCM is to analyze the failure consequences. This enables a company to decide if a failure mode is worth repairing before the functional failure occurs, or if it’s okay to wait until it does fail and simply replace it then.
About ASI: Andromeda Systems, Incorporated (ASI) is an ISO-9001:2008 company committed to superior technical performance and excellence in customer satisfaction. Our mission is to assist asset and fleet managers in achieving optimal levels of economy, availability, and safety by developing and applying leading systems engineering tools, processes, and expertise. We are headquartered in Virginia Beach, VA, with offices in Lexington Park, MD; Arlington, VA; Jacksonville, FL; Havelock, NC; Oklahoma City, OK and San Diego, CA.