The development of the General Purpose Simulation System (GPSS)

Abstract

The General Purpose Simulation System (GPSS) is a programming system designed for the simulation of discrete systems. These are systems that can be modeled as a series of state changes that occur instantaneously, usually over a period of time. Complexities in their analysis arise because there are many elements in the system, and there is competition for limited system resources. The simulation technique uses numerical computation methods to follow the system elements through their changes of state, and predicts properties of the system from measurements on the model. GPSS came into existence rapidly, with virtually no planning, and surprisingly little effort. It came rapidly because it filled an urgent need that left little time for exploring alternatives. The lack of planning came from a happy coincidence of a solution meeting its problem at the right time. The economy of effort was based on a background of experience in the type of application for which the language was designed, both on the part of the designer and the early users.