How to use the 'observe at what stage of operation' column in the FMEA table

[MikeS]

The FMEA table used in Module 1 of the course is a simplified version
of a full FMEA shreadsheet. The aim is to get students to do a simple
FMEA themselves so that they see what FMEA is used for, and hopefully
realise that it is a simple tool to analyse why equipment fails (it is
also a great technique to use in root cause analysis). Once you
understand the failure mode and its effect you then go into the RCM
stage and come up with those maintenance activities that prevent (or
at least detect) each failure cause that leads to each failure mode.

The column titled ‘observe at what stage of operation’ is used to
identify if the failure mode/cause under consideration happens at a
particular time when the equipment is used.

For example, snapped shafts usually happen on start-up, as do many
other overload failures because maximum torque is applied when an
electric motor starts. Hence in the column you put ‘at start-up’.
Later you would address how to manage start-ups so that the part is
not over-stressed and fails. You could suggest a design change to use
soft-starting or variable speed drive. You could also suggest that
the equipment is never started under load but always started empty and
the load is added once it is up to speed.

By recognising if a situation can cause the failure you make sound
choices that fit the operating particulars. If a failure cause does
not happen at a clear point during the equipment’s operation then
there is no ‘stage of operation’ and you mark the column as ‘N/A’—not
applicable.

That is how to use that question. Let me know if you want me to
explain it further.

You only really get a good handle of FMEA once you have done a 5 or 6
of them. But we all have to make a start somewhere.

My best regards to you all,

MikeS.