Abstract: A method of performing software validation testing on large electronic systems applies Usage Concepts specially modelled as Markov chains to forrealize the expected use of the system, to define the system behavior, and to introduce statistical measurements. The functional requirements of the software system are defined in a Markov chain by identifying a plurality of states through which the software system transitions when performing the functional requirements. Stimuli and responses which cause the software system to transition from one state to another are identified, and the probability of each state transition is calculated. Usage cases beginning at an invocation state and ending at a termination state of the software system are defined and listed in order of descending probability of occurrence in a Usage Profile. The Usage Profile, stimuli, and responses are automatically compiled into an automated test program, and associated test equipment is automatically programmed to generate a set of test cases.