DB2 & IMS

• Identifying characteristics of online IMS programs and copybooks: This included programs that used copybook DFHAID to indicate CICS usage and used copybook or macro DLIUIB to indicate the program used IMS. It also included items executed in an IMS Region in CICS or defined to a specific list or group for IMS in the CSD file.

Selecting Application Elements That Require Conversion

Next, we extracted and merged data from the application element files. The final files were imported into Excel spreadsheets that were used as checklists of JCL members, procedures, card members, programs, and copybooks to manage and monitor the project’s progress.

The relationships between application elements don’t lend themselves to simple unions because almost every relationship is many-to-many. That’s why we used an iterative process throughout the analysis. Each step added another relationship level, adding more jobs and programs to convert. For example, if a job executed one IMS program, other programs in the same job could be affected if the output of the IMS program changed. Similarly, a copybook used for an IMS segment might be used in a non-IMS program or job that didn’t execute IMS. These jobs and programs needed to be included in the conversion.

The analysis process provided the following lists:

• Batch and online programs that directly performed IMS functions or used copybooks that used IMS, or used called programs that used IMS

• Batch programs that used IMS segment layouts for input or output files

• Online programs that didn’t use IMS but used IMS segment layouts or commarea for processing

• Called subprograms used by the above that performed IMS functions

• Jobs that contained the above programs

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