Scheduling and sequencing in a machine independent command language
David Flint, Ian A. Newman · ITNOW · 1980
Abstract The scheduling of jobs to satisfy the user (ie choosing when they are to start, when the results must be returned by, and how important they are relative to other work) has been a relatively neglected area in conventional job control languages, since these have been developed with the primary objective of maximising workflow through the computer. Sequencing, where the running of one job, job step or program is conditional on the result of running one or more other jobs, job steps or programs, has also not been emphasised in most existing job control languages. However, these are both quite important matters as far as the individual user is concerned. The bcs jcl working group, which is working toward the specification of a ‘user-friendly’ machine independent command language, has therefore spent some time discussing the users’ requirements in these areas. This paper describes the results of these discussions. The general framework of bcs jcl has been described elsewhere [1, 2]. Throughout the paper examples of possible commands are given to illustrate the concepts being discussed. These examples are not intended to represent the language constructs to be used in bcs jcl.