| Failure Mode and Effect Analysis (FMEA) is a procedure
to identify all possible failure modes of components and
their impact on the functioning of the system. The rating is
based on the probability of the failure occurrence, the
severity of its effects and its detectability. Potential
failures with high rating represent the greatest risk and
should be eliminated. FMEA is a key tool in quality
improvement, the procedure is simple without statistics. The
key question in FMEA is: "How can the system
fail?" A new lock gate carried on wheels rolling on rails
failed after two years of service. Inspection leads to
severe wear of the wheel bearings. Some of the bearing
bushes where completely worn through and the shaft was
subsequently wearing the metal housing. Simple calculations
show that the specific wear rate of the bearings was not
higher than could be expected and thus predicted. If an FMEA
was conducted this possible failure mode was rated with a
high Risk Priority Number and corrective action was taken in
design stage.
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