Checking if a Job Should Run At All

Often, a job should only run if a certain test is passed. For example, an import task is to run subject to a condition, such as:

·	The user must provide a suitable filename

·	The file must not already have been imported

·	A stock amount recorded in the database must be down to a certain maximum.

You can include such a test at the beginning of the batch job using various means, for instance:

·	By using a table-base external set as input parameter set, and then defining constraints on this table that check the input parameter values.

·	By calling the job from a decision.

If you insert a separate test at the beginning of the batch job, you get better performance if the job fails, and you avoid unnecessary messages in status files.