TPS runtime reduction: A critical element in repair throughput

Test Program Set (TPS) runtime is one of the most important aspects in repair throughput. Considering the testing required to detect and isolate faults or failures and then verify repair during a typical maintenance event, the individual elements of a test program are usually executed at least twice. Any reduction in test execution time is therefore multiplied, increasing the importance of optimizing test execution speed to reduce overall repair times. Test execution speed is dependent upon the performance of several elements including the controller, instrument communication speed, instrument stabilization and measurement times, and UUT stabilization and response rates. Improving any one of these elements will improve test execution speed but understanding their interaction leads to the biggest performance improvements. Test execution time only tells part of the story. TPS setup, connection, and initialization time, degree of test automation, operator action, and fault repair time drive the overall repair process time. Typically TPS runtime metrics are tracked by measuring the end-to-end runtime excluding these factors. Even though this provides a more repeatable, measurable method of comparing test system performance, it does not completely account for the amount of time it takes to complete a maintenance event. This paper analyzes several methods of test time reduction and their potential to reduce runtime by profiling the contributing runtime elements of several real world test programs. The approach uses a simplified runtime prediction model to analyze the elements that drive test execution speed and quantifies their effects on TPS runtime and overall maintenance event time.