COBOL simulation: random number generation for binary and decimal computers

Abstract

Although the Common Business Oriented Language was originally designed for use in business data processing, the language is now being employed as a simulation language under certain limiting conditions. Factors influencing the application of the language to simulation studies include its popularity, its self-documenting characteristic, its "believability," and its efficiency in programming the triangular distribution.A necessary requisite in any simulation study is the programming of random number generators to simulate the random occurrence of various events. Several methods of generating random numbers are available, but the technique most frequently used is the power residue method. Since most simulation studies are programmed with FORTRAN (a general purpose language), simulation languages (SIMSCRIPT, GPSS, GASP, etc.), or machine languages, little attention has been devoted to programming the power residue method of random number generation with COBOL.A procedure is presented which describes and discusses COBOL programming of random number generation for the binary computer and the decimal computer utilizing the power residue method. Program excerpts are provided to illustrate the procedure, and comparative differences in COBOL programming for the two computer types are noted. Conditions most favorable to COBOL programming of simulation studies are also discussed, as well as the conditions under which COBOL programming is not recommended.