How does the scheduler help with job preparation?

The scheduler helps in two ways:

Runtime variables can often be automatically substituted, even if they vary from run to run. Many such variables are related to the date, and IBM Z Workload Scheduler can build a string in the format required by a program.
When jobs need manual job preparation, the administrator specifies a job setup operation as a predecessor for the job operation. The scheduler does not submit the job until you have finished preparing the job statements.
Do not edit and submit the job outside IBM Z Workload Scheduler. Instead, use the READY LIST panel to edit the job: IBM Z Workload Scheduler submits the job for you when you have prepared the job (and when other dependencies have been met).