A man/machine workload model

Abstract

The fundamental nature of computer systems is to serve the user. If we wish to evaluate the performance of a computer system, we must therefore seek to characterize its responsiveness to those actions initiated by the user. It is this responsibility that isolates accurate workload distributions as an imperative ingredient in computer systems evaluation, and it is this ingredient that the man/machine workload model addresses.In particular, the model presented here simulates human activity at a terminal in real-time or time-share computer system environments. The use of flowcharts to represent human decision making and a variable language definition capability to code flowchart actions are key to the approach. The techniques described stress automatic and manual verification as well as the ability to accurately represent workloads at the point where workloads originate, the human.With this representative approach, accurate workload generation is a natural outcome. In addition, experience has shown that the man/machine workload model serves to enhance computer system simulation credibility, provide a tradeoff tool for human factors and operations design "what-if" questions, and most importantly, to provide a validation methodology for front-end system design efforts.