Severity Classification

This classification is assigned to provide a qualitative measure of the worst potential consequences resulting from item failure or design error. Classifications should be assigned to each recognized failure mode and each item analyzed in accordance with the loss statements below. It should not be possible to identify an item or a failure mode according to the loss statements in the four categories below, but similar loss statements based on several inputs & outputs should be developed and included in the ground rules for the FMECA activity. Severity classification categories which are consistent with MIL-STD-882 are explained as follows:

Category I-Catastrophic

A failure that might cause injury or death.

Category II-Critical

A failure which might cause severe injury, major property damage, or major system damage that shall result in major downtime or production loss.

Category III-Marginal

Failure which might cause minor property damage, minor injury, or minor system damage which shall result in delay or loss of system availability or degradation.

Category IV-Minor

A failure not serious adequate to cause injury, property damage or system damage, but shall result in unscheduled maintenance or repair.

These categories might be observed through cost or any other factor, but while used in the established criteria, must be consistent throughout the analysis.