This paper discusses software techniques that enhance the ability of small portable ATE to effectively detect, prioritize, and isolate the location of multiple failures within complex electromechanical systems. The software is being implemented on RCA's STE-M1/FVS, a portable, microprocessor-based test set which supports the M1 Abrams Tank and M2 Bradley Fighting Vehicle. The software architecture allows the creation of a network of fault-tolerant parallel flow paths within test programs. This test architecture results in a maximal extraction of System-Under-Test (SUT) performance data regardless of the number of malfunctions existing in the SUT. A Test Design Language (TDL) that expedites the programming and documentation of these test programs and a Parallel Test Simulator (PTS) that aids in the design, development, and validation process have been developed to support the test architecture.