Second blog provides details on risk and criticality assessment. Risk and criticality assessment on equipment “Dewatering Pump” calculated risk score as “A – High”. With risk and criticality it is clear that the equipment “Dewatering Pump” is a critical equipment and it cannot be allowed to fail, to ensure there is no impact on environment and human life.
The next step recommended by the assessment template is FMEA assessment. Hence as a reliability engineer I will trigger the FMEA assessment for the equipment “Dewatering Pump”.
Failure Modes and Effects Analysis
FMEA is one of the best ways of analyzing potential reliability problems making it easier to take quick action and mitigate failure. FMEA is used to identify failure modes, their causes and impact on the asset or system. Highlights of FMEA are -
Identify and recognize potential failures including causes and effects.
Evaluate and prioritize identified failure modes based on RPN (Risk Priority Number).
Identify and suggest actions to either eliminate or reduce potential failures from occurring.
RPN = Severity * Occurrence * Detectability
RPN(FM) = Max RPN(Cause assigned to the FM)
RPN (Equipment) = Max RPN (FMs Assigned to the Equipment)
The company admin has to create the FMEA assessment template, the pre-cursor to create an assessment template are the below steps.-
Create a impact - In FMEA assessment, I would like to understand which failure modes are affecting impact which had higher risk score during risk and criticality. Hence, for FMEA I will continue to use the impact category -"Environmental Consequence"
Create severity scale with below options -
Create occurrence scale with below options -
Create detectabilty scale with below options -
As FMEA requires three specific dimensions of types - Severity, Occurrence and Detectabilty. I created three dimensions with respective scales created in previous steps.
Since FMEA is a complex process, while doing the assessment, only one impact is assessed at a time unlike risk and criticality where you can add multiple impacts. Also, to calculate RPN, three dimensions are required, namely severity, occurence and detectability. Hence in FMEA AT, only one impact and three dimensions are allowed.
Following the same steps as in risk and criticality AT, I have created a FMEA AT with one impact and three dimension -
I have maintained the threshold and added description based on the color.If the RPN score is in the red range, the recommendation is to continue with a deeper analysis and trigger a RCM assessment.
Similar to risk and criticality AT, you can assign equipment template so that it will be available as pending assessment in the equipment page. This will ensure that no assessment is missed out as proposed by the company admin.
Publish the FMEA AT, You can create a announcement which will help the reliability engineer to notify that a new FMEA AT has been published and reliability engineer can proceed with the FMEA assessment.
After the FMEA AT is published, it is available for the reliability engineer to proceed with the FMEA assessment. Reliability engineer can trigger the FMEA assessment from various touch points similar to risk and criticality like-
I will trigger the FMEA assessment from the second option. While triggering a FMEA reliability engineer also gets an option to decide whether to include all the sub components of the equipment. Since dewatering pump didnt have any sub components, I proceeded with selecting "No" as a option.
I maintain the required details during the FMEA assessment like description and previously created AT.
Similar to risk and criticality assessment, you can maintain scope description and roles information (if it is maintained in the FMEA AT)
Since I created the FMEA from option 2, the equipment is already assigned. If required reliability engineer can add more assets to the same FMEA. In case, the FMEA is created from option 1, reliability engineer needs to add all assets explicitly.
Navigate to "Assignment" section and click on the equipment to proceed with FMEA Assessment
The equipment has five FMs assigned and for each FM, we will assess the severity of the effect and based on that identify the RPN value of each cause. As mentioned above, maximum RPN value of cause will be assigned to the FM. The values can be maintained after setting the effect/cause tables in edit mode.The RPN of the cause is calculated as 4 * 15 * 15 = 900. Since, this FM has only one cause, RPN of the FM is also 900.
As FMEA is a process of identifying unknown causes and effects, you can assign new set of cause and effect during FMEA assessment also.
To identify the RPN of the equipment, I will assess all the 5 FMs assigned to the equipment. However in case, I dont proceed with calculating the RPN value of all the FMs assigned to the equipment, The equipment will get the max of the available RPN of the FMs.
There is an advance feature like system suggesting detectability and occurrence based on previous data maintained. Application checks if two assets have same FM, effect, severity of effect and causes are assigned to same effect then system proposes the detectability and occurrence for the causes. This supports the reliability engineer to fill in same kind of causes in the assessment.
I have done a similar assessment for another FM and cause and got the RPN score as 1600. Since this is the highest RPN, equipment will get the same RPN value. As it falls under the red threshold, the proposed next steps in the FMEA AT was RCM. This would mean, as a reliability engineer I will trigger a RCM assessment for this equipment.
If required, assign new set of FM, cause and effect during FMEA assessment. Once all the unknowns(FM, Effect, Cause) are identified, it is time to proceed to identify how to solve the problem. The reliability engineer will identify a set of recommendation which the maintenance planner will further take action on. Create recommendation for the causes for which you would like to resolve.
Recommendation can be created from four different sources as shown in the screenshot. Details on the recommendation will be shared blog series 6 which is dedicated to recommendation concept.
I created a preventive and corrective recommendation for the cause with highest RPN. Solving this particular cause will ensure that the equipment is working with minimal breakdown.
To ensure that no information is missed during the FMEA assessment, you can validate before publishing the FMEA. It gives details of all the assigned FMs, causes and effects, on which the assessment is not done. As shown in the screenshot, dewatering pump equipment has still few FM, cause, effect on which assessment is to be done. However during the assessment I have already identified the key cause which I would like to resolve, and calculated the RPN for the equipment, hence I will go ahead and publish the FMEA assessment.
Once published, the FMEA assessment details are available at the equipment page also.
The risk priority number in the indicator section is also updated.
As next steps of the FMEA assessment, I will start a RCM assessment for the dewatering pump equipment.
Before that, I will go back to my other equipment “Fire Fighting Pump” on which risk and criticality assessment was done. As the next steps, I will trigger the checklist assessment for the equipment.
In my next blog series I will cover checklist assessment for “Fire Fighting Pump”.