SIMULATING TRANSIENT-STATE SYSTEM EFFECTIVENESS FOR HUMAN-MACHINE SYSTEMS

System effectiveness is a combined measure of readiness and reliabilit y at each task-arrival time, when transient (human) operator behavior is considered in conjunction with the machine operating state. We deri ve effectiveness evaluation models for human-machine systems that have several machines. Each machine has an operator and contains several c omponents (hardware and/or software). The system is modeled as a serie s system where all components and operators must be ready and reliable for every task in a mission. The probabilistic model for system effec tiveness is quite complex in computation and provides solutions only f or the steady state of the system. Simulation is used to estimate the effectiveness of the human-machine system and to obtain the transient performance. The modeling and simulation techniques can also be used f or large human-machine systems that consist of computers, processors, and software. This study extends Abbas and Kuo (1990) that assumed one machine with multiple components in the human-machine system. Even on e more machine and one more operator can make the probabilistic model much more complex. We have learned that computer simulation is necessa ry to analyze such multiple human-machine systems.