Or PFEMA, Abbreviation for Process Failure Mode and Effects Analysis, which is a structured analytical technique used by a process responsible team/individual to identify potential failures of a process. Process FMEA helps to prioritize the necessary action to mitigate the risk.
It is a living document that should be initiated prior to process of production and maintained through the life cycle of the product.
Process FMEA ?
PFMEA defines the risk, analyses the effects, and evaluates each process step and assigns a risk score on a scale of 1 to 10 for the following variables:
- Severity — Assesses the impact of the failure mode (the error in the process), with 1 representing the least safety concern and 10 representing the most dangerous safety concern. In most cases, processes with severity scores exceeding 8 may require a fault tree analysis, which estimates the probability of the failure mode by breaking it down into further sub-elements.
- Occurrence — Assesses the chance of a failure happening, with 1 representing the lowest occurrence and 10 representing the highest occurrence. For example, a score of 1 may be assigned to a failure that happens once in every 5 years, while a score of 10 may be assigned to a failure that occurs once per hour, once per minute, etc.
- Detection — Assesses the chance of a failure being detected, with 1 representing the highest chance of detection and 10 representing the lowest chance of detection.
- RPN — Risk priority number = severity X occurrence X detection. By rule of thumb, any RPN value exceeding 80 requires a corrective action. The corrective action ideally leads to a lower RPN number.
How to Complete a Process FMEA
A simple explanation of how to complete a process FMEA follows below:- Form a cross-functional team of process owners and operations support personnel with a team leader.
- Have the team leader define the scope, goals and timeline of completing the FMEA.
- As a group, complete a detailed process map.
- Transfer the process map for the steps of the FMEA process.
- Assign severity, occurrence and detection scores to each process step as a team.
- Based on the RPN value, identify required corrective actions for each process step.
- Complete a Responsible, Accountable, Consulted, and Informed (RACI) chart for the corrective actions.
- Have the team leader on a periodic basis track the corrective action and update the FMEA.
- Have the team leader also track process changes, design changes, and other critical discoveries that would qualify and update the FMEA.
- Ensure that the team leader schedules periodic meetings to review the FMEA (based on process performance, a quarterly review may be an option).
