This paper describes the RTSS simulation-based performance evaluation method during the upgrade of the HT-7 data processing system to a distributed environment. We present the main concepts and steps of the method. Queueing modeling and steady-state operational analysis techniques are also used for analytic modeling. Both simulation and analysis studies on the HT-7 data processing system indicate that in comparison with conventional time-shared systems,a client/server system can significantly reduce the completion time of raw data display,real-time data processing and data transfer in the online system,raise the workload capacity and reduce the average waiting time of the off-line system.
