• IMS database names, segment names and the programs that updated them.
Using the files created in the first phase, we proceeded with the iterative process shown in Figure 2.
Assigning a Complexity Level to Each Application Element
To determine how many programmers and how much time would be required for the conversion, we assigned a complexity level to each program. A program of:
• Low complexity required only a few variable name changes and/or the addition of one or two SQL statements without affecting the logic of the program
• Medium complexity required some logic changes to replace IMS with DB2 (most didn’t perform updates to DB2 tables)
• High complexity needed to be almost completely rewritten and redesigned.
Because all the detailed information was available in the analysis files, we could quickly evaluate the characteristics of the application elements.