The DoD has achieved success with recent automatic test equipment (ATE) families, as evidenced by the navy's consolidated automated support system (CASS) and the army's integrated family of test equipment (IFTE) programs. However, as these systems age, the increased requirements for technology insertion due to instrument obsolescence and the demands of advanced electronics are becoming evident. Recent advances in test technology promise to yield reduced total ownership costs (TOC) for ATE which can incorporate the new technology. The DoD automatic test system (ATS) executive agent office (EAO) objective is to significantly reduce total ownership cost. Several objectives have been identified including use of synthetic instruments, support for legacy test product sets (TPSs), and more efficient ways of developing TPSs. The NxTest software architecture will meet the objectives by providing an open systems approach to the system software. This will allow for the incorporation of commercial applications in the TPS development and execution environments and support current advances in test technology.