MIL-STD-1629-RevA - Barringer and Associates, Inc.

MIL-STD-1629Awhere:C* = Criticality number for the item.n = The failure modes in the items that fall undera particular criticality classification.j = Last failure mode in the item under the criticalityclassification.4. Criticality matrix. The criticality matrix provides ameans of identifying and comparing each failure mode to all other failuremodes with respect to severity. The matrix is constructed by insertingitem or failure mode identification numbers in matrix locations representingthe severity classification category and either the probability ofoccurrence level or the criticality number (Cr) for the item’s failuremodes. The resulting matrix display shows the distribution of criticalityof item failure modes and provides a tool for assigning correctiveI action priorities. As shown in Figure 102.2, the further along the‘ dia~onal line from the crigin the failure mode is recorded, the greaterthe criticality and the more urgent the need for implementing correctiveaction. The example criticality matrix in Figure 102.2 was constructedto shc~w how either the criticality number (Cr) or probability of occurrencelevel can be used for the vertical axis. The completed criticalitymatrix shall be included in the FMECA report, General Requirements, 4.5.5. Ordering data. The following details shall be specifiedin the appropriate contractual documents:a. Task 101 (see 1.1 of Task 102).b. Analysis approach (see 3 of Task 102).c. Failure rate data source(s) (see 3.2 of Task 102)if quantitative approach is specified.