Pitfall 1 | Prioritizes, Doesn’t Correct
- The initial output of an FMEA is the prioritizing of failure modes based on their risk priority numbers.
- This alone does not eliminate the failure mode. Additional action that might be outside the FMEA is needed.
Pitfall 2 | Only as Good as the Team
- Identifying failure modes is a team brainstorming activity.
- If the team forgets to list it, an important failure mode could be left alone, waiting to occur.
Pitfall 3 | Time Consuming
- It takes time to get into the details.
Pitfall 4 | Unknown Unknowns
- Might miss a failure mode or an effect outside the experiences of the company.
Pitfall 5 | Not Customizing Rating Scales
- Rating scales should be meaningful to everyone in the organization.
- The generic rating scales might be confusing to some teams.
- Management will not be able to compare RPNs in order to prioritize activities between teams.
Pitfall 6 | Not Starting in the Design Stage
- The earlier in the design process an FMEA is started, the better.
- A DFMEA can catch where design verification is needed.
Pitfall 7 | Taking on Too Large a Scope
- Taking on an entire process may be a daunting task.
- Break a large process down into manageable chunks.
Pitfall 8 | Not Including Operators
- Experienced operators should be on the team to add their perspective.
- They often have good information on failure modes and on the effectiveness of control systems.
- They might have information on occurrence as well.
Pitfall 9 | Not Including Customers
- Customers, especially end-users, often have a better view on failure modes than internal personnel.
Pitfall 10 | Not Including Suppliers
- Suppliers also bring an outside perspective to the team.
- Might be able to tie your process in with theirs.
Pitfall 11 | Becoming a Full-Time Job
- Sometimes people use an FMEA as an excuse to get out of doing their regular job.
- You can’t afford to have people who are just conducting FMEAs.
- Won’t get their regular work done.
- Even if FMEAs are made their “regular” work, they will lose touch with the process and the FMEA will become mere paperwork.
Pitfall 12 | Not Using Concept of a Process
- This will cause the team to forget some failure modes.
- The team should brainstorm failure modes in each of People, Methods, Equipment, Materials, and Environment.
Pitfall 13 | Not Getting into the Details
- A superficial look at the process will miss many failure modes.
Pitfall 14 | Forgetting there are Internal- and External-Related Failure Modes
- Many FMEAs focus only on the customer requirements (specifications).
- Sometimes internal productivity losses, equipment damage, scrap, and rework have very severe effects on the company.
Pitfall 15 | Confusing Root Cause and Failure Mode
- Teams often have root causes as failure modes.
- A failure mode is the failure to perform the intended function.
Pitfall 16 | Not Looking at Each Product
- Templates are great but every product being made in a process is not exactly the same.
- The template should be used as a starting point and each product should be evaluated:
- Could this failure mode occur with this product?
- Would this effect occur?
- Is this the correct root cause?
- Are these controls applicable?
- Should any of the three ratings be changed?
Pitfall 17 | Assuming Detection Controls Are Better Than They Are
- Some controls are not as good as they are perceived to be:
- High repeatability and reproducibility.
- Don’t test for what we think they test for.
- Only test part of the product.
Pitfall 18 | Assuming Detection Controls Apply When They Don’t
- A control might apply to one effect of a failure mode but not another.
- For example, final inspection is a control against a defect impacting a customer, but it may not be a control against rework or scrap.
Pitfall 19 | Not Linking with Mistake-Proofing
- FMEA is a prioritization tool. It doesn’t eliminate failure modes or effects by itself.
- Companies need to apply tools such as mistake-proofing to eliminate the root causes of failure modes.
- This is especially true with failure modes that have very severe effects.
Pitfall 20 | Not Tying into Control Plans
- The control plan tells people how to react when a failure mode occurs.
- The FMEA will not be a living document if it is not tied to the control plan.
Pitfall 21 | Failing to Update the FMEA
- As new potential failure modes are identified, they should be added to the FMEA and control plans developed for them.
- It is critical that the template also be updated.