Job Processing
A job is a unit of work which can be made up of many job steps. job processing goes through a series of steps. There are 6 phases in job processing: 1. Input 2.Conversion 3.Execution 4.Output 5.Hard copy 6.Purge INPUT: During this phases job is read from internal reader, terminal and card readers. The Internal Reader is a special system program that is used by programs to submit jobs commands, and control statements to JES2 for processing. JES2 will read the job stream and assign each job an ID, (Job Number). The job stream will then be P laced into special JES2 spool datasets ready for processing. J ES2 will select jobs from the spool datasets for processing. CONVERSION: The JCL along with the PROC is converted into an interpreted text to be understand by JES and MVS. The text is stored into a dataset, which is called SPOOL. At this stage the JCL syntax is checked for errors.I f there are any errors then the job is queued for output processing and no p