5. A system for generating a test job control language (JCL) file, the system comprising: a processor; a memory device for storing a source JCL file including a plurality of jobs, and instruction files containing instructions for modifying the source JCL file according to a test environment, wherein the instruction files include: a global file containing instructions applicable to all jobs in the source JCL file; and a specific file containing instructions applicable to one of the plurality of jobs in the source JCL file; a JCL generation module executable by the processor and adapted to: determine all procedures that are referenced by the plurality of jobs in the stored source JCL file; open each unique procedure of the determined procedures once; and modify the plurality of jobs in the source JCL based on the instructions in the instruction files and the opened procedures to generate a test JCL file.
5. A system for generating a test job control language (JCL) file, the system comprising: a processor; a memory device for storing a source JCL file including a plurality of jobs, and instruction files containing instructions for modifying the source JCL file according to a test environment, wherein the instruction files include: a global file containing instructions applicable to all jobs in the source JCL file; and a specific file containing instructions applicable to one of the plurality of jobs in the source JCL file; a JCL generation module executable by the processor and adapted to: determine all procedures that are referenced by the plurality of jobs in the stored source JCL file; open each unique procedure of the determined procedures once; and modify the plurality of jobs in the source JCL based on the instructions in the instruction files and the opened procedures to generate a test JCL file. 6. The system of claim 5 , wherein: the global file includes instructions for substituting at least one reference in the source JCL file with another reference; and the instructions in the specific file override the instructions in the global file.