FMEA in the machining process
Six Sigma – iSixSigma › Forums › Old Forums › General › FMEA in the machining process
- This topic has 4 replies, 4 voices, and was last updated 15 years, 5 months ago by
kamon.
-
AuthorPosts
-
December 20, 2006 at 11:28 am #45582
Hi
Ive always have problem with Occurrence, but its hight time to solve it with your help
Example from the machining:
Potential mode failure : lets say a diameter is out of tolerance – too small and a part cannot be fixed somewhere.
Potential cause: a broken tool
According to FMEA reference manual: occurrence is how frequently the specific failure cause/mechanism is projected to occur but next in the table there is probability of failure so Im a bit confused.
Which question below best describe occurrence, in your opinion?
How often the tool breaks?
How often the diameter is too small?
How often the diameter is too small when the tool is broken? (almost always when an internal diameter is concerned)
How often the tool breaks and causes the diameter too small?
Thank you0December 20, 2006 at 2:03 pm #149322Occurrence is related to the specific cause (#1, tool breaking), since the undersize diameter could be caused by more than one cause, and each is addressed separately.
0December 20, 2006 at 4:40 pm #149327
The ForceMember@The-ForceInclude @The-Force in your post and this person will
be notified via email.Use #4 because occurrence rating is for the causes or each cause that relates to the failure mode
0December 20, 2006 at 5:43 pm #149331
FlaviusParticipant@FlaviusInclude @Flavius in your post and this person will
be notified via email.I agree with Duke’s post, I have the same interpretation of the occurence.
0December 21, 2006 at 7:36 am #149372Thx
I must admit that agree with you all, but for me #4 is the best
Probably the example is not good because as I wrote a broken tool almost always causes an internal diameter undersize.
What if there is three different causes:
– wrong tool setting
– tool breaking
– machine malfunction
for me the questions should be:
– How often a tool is wrongly set and causes the diameter undersize?
– How often a tool breaks and causes the diameter undersize?
– How often machine malfunction causes the diameter undersize?
Because wrong tool setting and machine malfunction can cause the diameter oversize as well.
Am I right?0 -
AuthorPosts
The forum ‘General’ is closed to new topics and replies.