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A
astudent
examples?
can somebody send me examples of already done PFMEAs?
for a big plant is better to list process steps of product items?
can somebody send me examples of already done PFMEAs?
for a big plant is better to list process steps of product items?
Ron Rompen
Trusted Information Resource
Attached are two completed PFMEA's that I have successfully submitted to our customer. Hope you find them of some assistance.
If you would like to discuss further, don't hesitate to PM me here (my email is down right now for some unknown reason).
Hmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm
For some unknown reason, it will not allow me to attach my demo files. Email my at my alternate address (Thylanes@gmail.com) and request them, and I will send them off to you.
If you would like to discuss further, don't hesitate to PM me here (my email is down right now for some unknown reason).
Hmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm
For some unknown reason, it will not allow me to attach my demo files. Email my at my alternate address (Thylanes@gmail.com) and request them, and I will send them off to you.
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Bill Ryan - 2007
Welcome to the Cove 
For a beginner (my assumption), the simplest way I 've come across is to define a Failure Mode as "meaureable on the product" and a Failure Cause as "measureable in the process". The vast majority of our Failure Modes are part/packaging characteristics with a sprinkling of "uptime", "utilization", "internal scrap", etc. Another way to look at it might be "What is the expected output of the process step" (if not attained - Failure Mode) and if that expected output had a "hiccup", what, in the process, caused it.
We list all our Potential Failure Modes and then, at each processing step, decide if we can have an impact on them at that step. Fortunately, our software (QPLUS) makes that excersize pretty simple.
Hope that helps a little.
For a beginner (my assumption), the simplest way I 've come across is to define a Failure Mode as "meaureable on the product" and a Failure Cause as "measureable in the process". The vast majority of our Failure Modes are part/packaging characteristics with a sprinkling of "uptime", "utilization", "internal scrap", etc. Another way to look at it might be "What is the expected output of the process step" (if not attained - Failure Mode) and if that expected output had a "hiccup", what, in the process, caused it.
We list all our Potential Failure Modes and then, at each processing step, decide if we can have an impact on them at that step. Fortunately, our software (QPLUS) makes that excersize pretty simple.
Hope that helps a little.
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R
Ross_Henderson - 2005
The best way to get your failure modes I have found is by reviewing previous failures, brainstorming with the process owners/engineers/operators, equipment engineers etc.
I would regard any process failure that results in scrapping, rework or extra testing as a failure mode. You will never be able to find all the failure modes but you can add the ones that you havn't identified to later revisions of your FMEA docs.
If you have any sister plants or good ties with other companies carrying out similar processes you should also ask them for failure modes they have experienced.
Hope this helps.
I would regard any process failure that results in scrapping, rework or extra testing as a failure mode. You will never be able to find all the failure modes but you can add the ones that you havn't identified to later revisions of your FMEA docs.
If you have any sister plants or good ties with other companies carrying out similar processes you should also ask them for failure modes they have experienced.
Hope this helps.
M
M Greenaway
I would advise looking at each process step, determine the objective of this process step, then think how this objective may fail to be achieved.
e.g. If your process step was 'insert pin into hole', your failure modes might be 'pin partially inserted' or 'pin over inserted' or 'missing pin', etc
e.g. If your process step was 'insert pin into hole', your failure modes might be 'pin partially inserted' or 'pin over inserted' or 'missing pin', etc
A
astudent
of course you all are helping me. thank you
It seems that the process of listing all possible modes is more of an art than a science.
Is also possible to read drawings and to take a special look at critical dimensions?
It seems that the process of listing all possible modes is more of an art than a science.
Is also possible to read drawings and to take a special look at critical dimensions?
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A
astudent
how many RPN?
Suppose a failure mode derives from the delivery of wrong material from a supplier.
If the control is just the reading of the delivery note, I have 2 chances: 1)delivery note is correct and so detectability=1,
2) delivery note wrong, detectability=6.
Which indice should I write? Both?
Don't should I have just one RPN per failure mode?
Suppose a failure mode derives from the delivery of wrong material from a supplier.
If the control is just the reading of the delivery note, I have 2 chances: 1)delivery note is correct and so detectability=1,
2) delivery note wrong, detectability=6.
Which indice should I write? Both?
Don't should I have just one RPN per failure mode?
Ron Rompen
Trusted Information Resource
You can have several RPN's for the same failure mode, as you can have many different root causes. Try and determine which are the most likely (based on past history, product and process knowledge, team feedback, etc) and include those.
Each on should have the same SEV score, but the OCC and DET can be very different, as can the Prevention and Detection entries.
And if all else fails, ask your customer. What do they expect? Are they willing to assist with input into your PFMEA meetings?
Each on should have the same SEV score, but the OCC and DET can be very different, as can the Prevention and Detection entries.
And if all else fails, ask your customer. What do they expect? Are they willing to assist with input into your PFMEA meetings?
