MIL-STD-1591A, MILITARY STANDARD: COMMAND, CONTROL AND COMMUNICATIONS (C3) SYSTEM AND COMPONENT FAULT DIAGNOSIS, SUBSYSTEMS, ANALYSIS/SYNTHESIS OF (08 DEC 1978) [MIL-STD-001591A USED IN LIEU OF MIL-STD-1591] [NO S/S DOCUMENT]., This standard establishes uniform criteria for conducting trade studies to determine the optimal design for command, control and communication systems and component fault diagnosis/isolation subsystems, hereafter referred to as Fault Identification & Test Subsystems (FITS).