Failure Mode and Effects Analysis (FMEA) breaks down each step of a process or the design of a service, or product, to identify risks and possible errors that can occur. These risks can come from a variety of places such as user error, defect materials, incorrect machinery and even the environment itself.
There are 7 steps to the FMEA process, with 3 main paths of the analysis itself. These steps are as follows:
1. Pre-Work and Team Assembly
One of the reasons FMEA work so well is the combined knowledge and experience of its team members. The team is made up of individuals from all aspects of the design or process, including managers down to floor staff who can all offer their own insight.
The pre-work involves correlating important documents, either through creation or from current records to aid in understanding the pre-existing risks and the flow of the process itself. The required documents are:
- Failure Mode Avoidance Past Failure
- Block Diagram – for Design
- Parameter Diagram – for Design
- Process Flow Chart – for Processes
- Characteristics Matrix – for Processes
- A Pre-work Checklist – requirements to be included, assumptions and potential causes.
2. PATH 1 – Requirements Through Severity Ranking
Using the pre-work documents this step gathers information on the functions, failures, and effects of those failures as well as assigning them a severity ranking.
Functions are the areas that are being analyzed such as the specification of a design or the desired process outputs.
Failures are noted in 5 ways depending on the level of failure. Full Function failure, Partial/Degraded failure, Intermittent Function failure, Over Function failure or Unintended Function failure.
Effects are the consequences of the failure and are ranked based on the severity of the consequence. If ranking is 9 or 10, then action may be taken at this step.
3. PATH 2 – Potential Causes and Prevention Controls through Occurrence Ranking
Causes, both known and potential, are chosen from the design or process inputs and applied to specific failure modes. The current prevention controls, as well as the occurrence ranking (how often each failure mode happens) of each cause, is documented, alongside and classification of special characteristics if indicated.
4. PATH 3 – Testing and Detection Controls Through Detection Ranking
Detection controls are put in place to verify that the design meets the requirements and to avoid cause or failure modes from getting through undetected to the customer. If current controls are insufficient to handle the risks identified new controls are put in place, and Control Plans are updated.
5. Action and Priority
All the actions selected in Paths 1, 2 and 3 are then assigned a rank number known as a Risk Priority Number (RPN) to organize the order in which actions are taken. Actions should not be determined based upon an RPN threshold as this can have a negative impact on the success of FMEA.
RPN is calculated by multiplying the Severity, Occurrence and Detection rankings for each failure/effect and cause and control combination.
6. Actions Taken/Review
Once countermeasures have been taken and risks are reduced, the FMEA actions can be classed as closed. If the risk is not reduced, then the FMEA needs to be rerun to improve the results and value added to the design or process.
7. Re-Ranking and Closure
Once the Risk Mitigation Actions are confirmed successes, the team must re-rank the Severity, Occurrence or Detection ranking values. These are then used to calculate a new RPN and is compared to the original RPN to confirm the relative improvement to the design or process.
The FMEA process needs to be repeated at least yearly but also whenever a change in the product, service or process occurs; or if they are applied in a new way. The repetition of the process aids in continuous improvement through the organization by constantly reducing risks and improving the health and safety of the working environment.
Looking for help to create an FMEA process? Contact McDonald Consulting Group to help. We will help you evaluate your needs, and come up with the most cost-effective solution with easy implementation for your organization. McDonald Consulting Group offers both in-house classes (which may be customized) and public offerings.