Test changes to COBOL DB2 program

Test changes to COBOL DB2 program

There is a production JCL which has two steps. One step runs cobol db2 programs A and the other step runs COBOL DB2 program B.

The Output of program A is used by program B. Program A has been changed, now how should I go about testing the changes of program A?

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While answering keep in mind, What all changes would be done to the production JCL to make a test JCL (like changing the loadlib etc) and would both the programs need to be recompiled and rebound or only program A or only program B or none.