JCL generation

Parameters (from the product options file [POF] and Execution panels) are passed to Batch Execution JCL Generation using the AJXIN or AJXPOFIN input streams. These parameters include the names of input files, JCL files, and the diagnostic output files. (For more information about the AJXIN and AJXPOFIN input streams, see Keywords-and-variables.)

After the data set names have been resolved, the JCL Generation component performs the following functions:

• Scans the input worklist for all utilities and commands that will require JCL.

• Analyzes each utility command for its DD requirements.

  Depending on the override options that you select, the following tasks might be performed for each identified DD:

  • Sizing the data sets.
  • Using the values specified for using DASD or tape units, as well as the values for tape-related options.
  • Using the values specified for the SMS and alternate SMS data sets, data set thresholds, and alternate units.
  • Processing the options for image copy GDGs.

  For more information about override options, see Default-JCL-Generation-option-overrides.

• Resolves the names of work data sets that JCL Generation passes from the JCL Generation option panels, such as SORTWORK, and the unload data sets that Execution uses.
• Merges DD statements (for example, SYSUT1 or SORTWORK) that more than one command uses so that the component does not generate duplicates and uses the highest estimated space.

JCL Generation either performs standard ISPF file tailoring or simulates file tailoring by using compiled skeleton libraries (SLIBs) to generate JCL. A large number of symbolic variables are available to automatically vary the JCL generated according to, for example, the subsystem name and the database name. These symbolic variables are listed in Symbolic-variables-for-BMC-Administrative-products.

The generated JCL includes DD statements for all data sets that the job or the Execution component needs, as well as the EXEC statement for the program and any necessary control parameters. For many of the work data sets that Execution uses, you can create the JCL for a cleanup job step that automatically deletes the work data sets at the end of the run. Other data sets are commented out in the JCL, providing you with the option to delete these as well.