In continuation of my ASPM blog series, I will continue to focus on the 3rd step in which I will take up RCM assessment.
In my previous FMEA blog, I did FMEA assessment on “Dewatering Pump” and the RPN for the equipment was 1600 which indicated that I should proceed with the RCM assessment for the equipment.
Highlights of RCM assessment –
- RCM assessment is a complex process in which all the unknown of the asset is identified, hence it requires a team who are well versed with the asset and its current maintenance strategy.
- The very first step of RCM is to define its operating context and required functions under it. The logical starting point is to understand what is being demanded from the asset. The RCM team must describe functions – All primary and secondary functions of the asset is been identified.
- Functional Failures – A functional failure is defined as “a state in which a physical asset or system is unable to perform a specific function to a desired level of performance”. It is instrumental to have a perfect understanding of the asset functions and the desired performance level to determine functional failures. The asset may not be able to fulfill a function at all or that it may perform it at a lower than the desired performance level.
- Failures Mode – A failure mode is a single event, which causes a functional failure to occur and each failure mode usually has one or more causes. So, we need to brainstorm on all possible events causing assets to impair their ability to perform each specific function to the desired levels of performance.
- All failure modes reasonably likely to cause each functional failure shall be identified. The method used to decide what constitutes a “reasonably likely to occur” failure mode shall be acceptable to the owner or user of the asset. Usually consensus is used to decide which failure modes to analyze and which ones to discard. Human and design errors causing failure event must be included in the failure mode list unless they are being addressed by other analysis methods.
- Failure Effects – Failure effects quantify the “damage” each failure event may cause to the plant or the organization. It is recommended to describe “what happens when the failure mode occurs”. Failure effects help determining the extent to which each failure mode is relevant .
- Consequence evaluation – Failures effects are classified into categories based on evidence of failure, impact on safety, the environment, operational capability, and cost. We should be able to decide which of the four categories apply to each failure mode effects. Only one category must be chosen – whichever is most severe. Hidden and evident failure modes must be clearly separated. Failures with safety or environmental impact must be distinguished from those only having economic impact either by operational or non-operational consequences. Like every step within the RCM process, failure consequence determination is critical. Maintenance strategies are carefully selected for every critical failure cause based on a decisional procedure using the failure consequence as the starting point.
There are different flavors of RCM assessment-
- Few organizations, do RCM along with consequence evaluation at the effect level
- Few other organizations, combine FM and cause together.
- While few prefer to do risk assessment at effect or FM level during RCM – (Future scope)
To keep the example simple, I will do the RCM assessment without combining FM and cause and do a consequence evaluation at the effect level. Advanced checklist template is used to create the consequence evaluation flow.
Creating a RCM template is different from other template creation where you would add impact, dimension etc. RCM template creation is a simpler process where you add the advanced checklist template details to create the consequence evaluation and other mandatory details.
Along with below information, in RCM template you will maintain the roles and assignment details also. The usage of roles and assignment is same like other templates. With role setup, you can define which roles are required as mandatory or optional in the RCM assessment. Assignment tab ensures that company admin assigns equipment template and all equipment from the equipment template should use the respective RCM template for RCM assessment. This information is available in the pending assessment in the equipment page.
To trigger a RCM assessment, it is possible from four places similar to other assessment. For RCM, I will trigger it from RCM application itself
- Navigate to RCM assessment tile in the FLP. It will display the list of all RCM assessment done in the system. Click on “New” and maintain the details. I will use the RCM template which was created earlier. Once the RCM assessment is created, you can maintain the scope description and roles for the assessment.
- Since I created the RCM from the RCM tile directly, hence no asset is assigned. I will explicitly assign the “Dewatering Pump” in the RCM assessment.
- Each asset can be used in a different context, for example pump getting used in cold region and in desert region will have different set of issues and resolution. Hence it is absolute necessary to understand the operating context in a RCM assessment. From the “Context Information” you can maintain the operational context. Based on the operational context the functions and functional failures are determined.
- Along with operational context, all the maintenance planes associated with this equipment in ERP is also available in the context information. Knowing how the asset is getting maintained currently, will help me as a reliability engineer to decide on the failure modes and its effect. Also I can created new set of recommendation based on the maintenance plan in the ERP.
- Based on the context information available I have assigned the below set of data in the RCM assessment. Same like FMEA assessment, RCM assessmnet is also to find the unknown details of the asset and you can assign functions, functional falures, failure modes and effects. If required you can also create new data during the RCM assessment.
- Once the entire data is assigned, we will proceed with consequence evaluation of the effect. Each node provides details on clicking on the “i” button.
- In the details part, you get various options like editing the function, functional failure, failure mode, effect’s short and long description. You can also view the hierarchy of the details.
- The consequence evaluation is done using the advanced checklist template which was assigned in the RCM template.The selected answers is also shown in the simulate button which helped to the flow of the answers in the consequence evaluation
- The entire process of RCM is completed when the reliability engineer creates a set of recommendation. I will provide details of recommendation in my next blog series.
- All the RCM assessment created for the asset is available in equipment page.
I will publish the RCM assessment after I have created the set of recommendation, hence for now I have kept the RCM assessment unpublished.
In my next blog series I will cover recommendation creation which is possible from both FMEA and RCM assessment.
Series 5: Reliability Centered Maintenance (RCM)
Series 6: Recommendation
Series 7: Preventive Maintenance Review (PMR)