MTTR Calculations per Procedure 5A
If Procedure 5A is selected under Maintainability in the System file properties, the specified MTTR is ignored. In this case, MTTR is calculated as indicated by MIL-HDBK-472 Procedure 5A. For more information, see Maintainability System File Properties.
The following tables, taken from MIL-HDBK-472, summarizes Procedure 5A calculations.
Isolation to a Group of RIs — Iterative Replacement
Maintenance Philosophy
Single Access
Multiple Access
Reassembly Required for Checkout
Reassembly Not Required for Checkout
Reassembly Required for Checkout
Reassembly Not Required for Checkout
Preparation T P
Fault Isolation T FI
Disassembly/Reassembly T D /T R
Interchange T I
Alignment T A
Check Out T C
Startup T ST