Failure Mode Criticality Number

The failure mode criticality number is the criticality of an individual failure mode. It is that portion of the item criticality number attributable to one failure mode in a particulare severity classification. It is often abbreviated by the symbol Cm. The formula is:

Cm = λptαβ


Nomenclature
symboldescription
λppart failure rate
tspecified time interval
αfailure mode ratio
βfailure effect probability