A Failure Modes Effect Analysis (FMEA) is an extremely powerful tool that all people can and will benefit from no matter your occupation or status in life.
Tonight, we shall discuss the history of the FMEA, the different types of FMEA, and finally how to actually construct one. At the end of the post is a free FMEA template for your downloading pleasure.
History
The FMEA is not a new tool. The aerospace industry used the FMEA during the Apollo missions in the 1960s. Later in 1974 the US Navy developed MIL-STD-1629 which discussed the proper use of the tool. And around this time the automotive folks latched onto the tool and never let go. Today, the FMEA is universally used by many different industries.
Type of FMEA
There are three main types of FMEA in use today.
- System FMEA: Used to analyze complete systems and/or sub-systems during the concept of design stage.
- Design FMEA: Used the analyze a product design before it is released to manufacturing.
- Process FMEA: Used to analyze manufacturing and/or assembly process.
The Process FMEA is probably the most commonly used and is also the least complex, in most cases.
10 steps to creating a FMEA
- List the key process steps in the first column. These may come from the highest ranked items of your C&E matrix.
- List the potential failure mode for each process step. In other words, figure out how this process step or input could go wrong.
- List the effects of this failure mode. If the failure mode occurs what does this mean to us and our customer… in short what is the effect?
- Rate how severe this effect is with 1 being not severe at all and 10 being extremely severe. Ensure the team understands and agrees to the scale before you start. Also, make this ranking system “your own” and don’t bother trying to copy it out of a book.
- Identify the causes of the failure mode/effect and rank it as you did the effects in the occurence column. This time, as the name implies, we are scoring how likely this cause will occur. So, 1 means it is highly unlikely to ever occur and 10 means we expect it to happen all the time.
- Identify the controls in place to detect the issue and rank its effectiveness in the detection column. Here a score of 1 would mean we have excellent controls and 10 would mean we have no controls or extremely weak controls. If a SOP is noted here (a weak control in my opinion) you should note the SOP number.
- Multiply the severity, occurrence, and detection numbers and store this value in the RPN (risk priority number) column. This is the key number that will be used to identify where the team should focus first. If, for example, we had a severity of 10 (very severe), occurrence of 10 (happens all the time), and detection of 10 (cannot detect it) our RPN is 1000. This means all hands on deck… we have a serious issue!
- Sort by RPN number and identify most critical issues. The team must decide where to focus first.
- Assign specific actions with responsible persons. Also, be sure to include the date for when this action is expected to be complete.
- Once actions have been completed, re-score the occurrence and detection. In most cases we will not change the severity score unless the customer decides this is not an important issue.
Dynamic Document
The single biggest failure people make with FMEAs is to spend time completing the document and then storing it in a file cabinet somewhere. The FMEA is the ultimate dynamic document meaning it lives as long as the process or product it is associated with does. Please use them!
Free Template
Here is a free FMEA Template for your use. Simply “right click” the link and choose “Save Target As.”
Feel free to share this template with as many people as you like. Also, please email me if you have any questions about this or any other continuous improvement topic.
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Great post. Very useful. Thanks.
No problem. Glad you liked it Jon.
It may be easier to understand and keeping with the high numbers being bad, if you look at 6. above as being the “probability” or chance that the error will reach the customer. From teaching many Green Belts, I find that they generally find it easier to understand.
Excellent post. Having recently moved from a very large and strictly controlled organisation, process wise and with a heavy focus on quality, to a ‘less focused’ and much smaller organisation, its uselful for me to see the workings behind decisions I previously took for granted.
@ vern – Great point and one I should have mentioned. Thanks for pointing it out.
@ Gar – Thanks for the compliment. I am glad you found it useful. Please let me know if you ever have any questions or have an idea for a future topic that may help you out.
I recently attended to a FMEA 4th edition training and the trainer said that the Key date in the PFMEA header must be keep updated, I did not know this, but he said that every time we update the PFMEA to implement new actions adding the promise dates for implementation, these dates shall not exceed the new key date.
Can somebody tell me if this is true. I read the FMEA manual and I did not find any comment regarding this.
Hi Rosalina, this sounds logical but I wouldn’t get too worried about details such as this… you’ll be better off focusing your energy on driving actions based on the results of FMEA. Good luck!
The key date can’t be any later than the PPAP due date.
Any revisions made to the fmea should be dated in the Revision Date.
Do this 10 steps still valid for new 4th FMEA? I think we should consider step 7 and 8, since now, we can use another focus than RPN, e.g. SOD, SO and SD. Correct me if I’m wrong. http://cisca.co.nr
Excellent post. Simple and very helpful. Tks.
I take training fmea from you,
Hey there’s some great FMEA info here I love it. I’m wondering though if there are any other websites where I can find FMEA worksheets or FMEA templates to download?