FMEA and You
By Robert A. Dovich, ASQ, Fellow, CQE, CRE, Quality Manager, Field Fastener Supply Company
To properly evaluate a process or product for strengths, weaknesses, potential problem areas or failure modes, and to prevent problems before they occur, it may be necessary to use a Failure Modes and Effects Analysis (FMEA). An FMEA provides a systematic method of resolving the questions: "How can a process or product fail? What will be the effect on the rest of the system if such failure occurs? What action is necessary to prevent the failure?"
You may have noticed the omission of, "Will it fail?" This will be determined a little later in the probability statement on likelihood of occurrence.
One difficulty with FMEAs is that, to properly perform the activity, it is necessary to objectively question a design for adequacy.
And people who design a process or product are reluctant to admit that potential weaknesses exist. Therefore, the FMEA should be a team action that consists not only of the designers, but also other personnel that are qualified to critique designs constructively and offer potential solutions.
While a Process FMEA and a Design FMEA differ in the areas being analyzed, the thought process is similar. The FMEA should generally be performed during the design-and-development stage. The earlier a change is found to be necessary, the lower the cost of making that change. Steps in performing an FMEA are not difficult, but do require that a logical sequence of events be followed and that actions be documented. The steps in performing a Process FMEA follow:
1. Do not try to use memory or the written routing alone to review the flow of a process-use a flow chart indicating the activities taking place at each operation. Criticality of the dimension or process output should also be documented.
Depending upon the end user of the FMEA (customer), specific headings, model years, drawing release dates or