ABSTRACT
This chapter describes how General Purpose Simulation System (GPSS) programs are executed by giving a precise formulation of the mechanism that moves transactions. It also discusses the use of random number generators, functions, and a number of additional blocks. As the GPSS processor steps through a GPSS program, in addition to generating code, it assigns the block numbers sequentially to every block in the program and places a transaction on the Future Events Chain whenever it encounters a GENERATE block. Variables are used in GPSS to express relationships among various model entities. Evaluations of arithmetic expressions are done through the VARIABLE construct. Each implementation of the GPSS must cope with a fixed memory size by imposing a limit on the maximum number of the transactions that can be made available. The intervals between the snapshots are regulated by a snap interval counter maintained by the GPSS.
