iSixSigma

Process Failure Modes Effects Analysis (PFMEA)

Definition of Process Failure Modes Effects Analysis (PFMEA):

Don’t we all strive to eliminate or reduce the probability of a defect or failure ever getting to our customer? Do you want to be proactive in recognising and evaluating potential process failure modes?

If you are answering yes to these questions, then process failure mode and effects analysis (PFMEA) could be right for you; let’s investigate further.  

Overview: What is PFMEA? 

Process failure modes and effects analysis is most often described as a systematic group of activities fundamentally intended to:

  • Recognise and evaluate potential failures of a process
  • Assess the effect of the failure
  • Document what actions can be taken to reduce or eliminate the failure occurring

PFMEA is well used across a wide range of businesses and industries, forming a fundamental part of continuous improvement and utlising methodologies such as process mapping.

We should consider the use of PFMEA whenever we have a process or service that’s being designed or configured, or maybe has a significant change of use.

Fundamental to developing a PFMEA is understanding and assigning Severity (S), Occurrence (O), and Detection (D) and the resultant Risk Priority Number (RPN = S*O*D). These terms will be explained later in this article. (If you want to know more about FMEA in general and industry governance, take a look at SAE J1739.)

2 benefits and 1 drawback of PFMEA 

Reducing — or even better, eliminating — the probability of a failure ever reaching the customer is a fundamental part of a Six Sigma approach. Let’s take a look at some benefits and drawbacks of using PFMEA.

1. Reduce rework cost and timing with PFMEA 

We can achieve the biggest benefit by starting the PFMEA before a process failure mode has been incorporated into the process. 

2. Capture risk reduction with PFMEA 

Having a formal process and record of your risk and defect reduction actions is really helpful as you develop your process or service. It’s also perfect for knowledge sharing across teams and preventing recurrence. 

3. Don’t underestimate the time and resource to successfully implement PFMEA  

Development and delivery of a high-quality PFMEA takes time, commitment, and resources — all of which need to be recognised and accounted for in work tasks and project planning.

Why is PFMEA important to understand? 

In using PFMEA, we have a systematic and logical group of activities that helps us develop and deliver robust processes and services.

You define all your potential process failure modes and their effects

There can be multiple potential failure modes, and these should be described in physical terms. The effects of a failure can be described as what is experienced by the downstream customer, then the failure effect is assigned a Severity (S).

You analyse all the potential process causes for failure 

There may be more than one cause per failure mode, especially when considering customer usage and operating conditions. For all potential causes, an assessment of how often this cause of failure will happen is assigned — known as Occurrence (O).

You assess your current failure management controls and decide if further mitigation is required

All of the current controls in place to detect causes of failure modes are captured and assessed for their effectiveness, known as Detection (D). 

The calculation of a Risk Priority Number (RPN = S*O*D) can be used to agree upon recommended actions to further mitigate risk.

An industry example of PFMEA 

During the COVID-19 global pandemic, many organisations implemented significant changes to their business processes. When developing an all-new online patient consultancy service, a large healthcare provider embraced process failure mode and effects analysis early in the project.

Utilising a cross-functional team with FMEA experience, the organisation identified the failure modes, effects, and causes in each process step and reviewed what process controls needed to be in place to ensure that they minimized incorrect or misdiagnosis of a patient symptom.

The online patient consultancy system was launched ahead of program schedule, on budget, and with excellent customer feedback — in many ways thanks to the diligent and timely utilisation of process failure mode and effects analysis.

3 best practices when thinking about PFMEA

In common with many process-driven activities, there are a number of fundamentals to get right that will help us with delivery.

1. Start early  

Never complete PFMEA as an “after-the-fact” exercise. Up-front time spent properly completing a PFMEA, when those process changes can be most easily and inexpensively implemented, will minimize late-change crises and improve customer satisfaction.

2. Support the team 

Make sure team members are knowledgeable on how to conduct a PFMEA, and use facilitators if you need to. Assembling the correct cross-functional team that has experience conducting PFMEAs is vital.

3. Stick with it 

You want to make the PFMEA a living document. Generating a PFMEA requires a significant investment in resources and time, so keep it active through the process lifecycle, and make it available for other colleagues in your business to learn from.

Frequently Asked Questions (FAQ) about PFMEA

1. What RPN should I target? 

There is no simple answer here — it will depend upon your products, processes, and quality history. Review those high Severity failures coupled with medium to high Occurrence, and prioritise your actions against these failure modes.

2. Does PFMEA only apply to manufacturing and assembly companies? 

Definitely not. Whilst you will see many examples of PFMEA from classic manufacturing and assembly industries, it’s equally valuable in customer service and business transactional companies. 

3. Is PFMEA required for ISO9001? 

No, but quality standards such as ISO9001 often require a business to identify, evaluate, and address risks, PFMEA may be used as part of a business process risk analysis.

One final thought on PFMEA

If you want to chase down the risk of an error or defect ever reaching your customer, utilising PFMEA is a proven systematic and qualitative approach that delivers real results.

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