Test instruments constituting an automatic test system are characterized in terms of execution time data. The execution time data is composed of a set of execution times. Each of the execution times is the time required for the test instrument to perform a respective testing operation. The test instruments additionally have the ability to communicate their respective execution time data to such recipients as others of the test instruments, the system controller and recipients outside the automatic test system. Additionally, such test instruments have the ability to communicate test results to at least one other of the test instruments and the ability to process test results received from at least one other of the test instruments. Such characterization, communication and processing allows a system integrator to devise execution time-dependent test programs as part of a test suite that allows test throughput to be maximized.