The IBM migration guides can help you identify some of the desirable functions you might want to look for in LE migration tools, including the ability to:
- Handle application inventory verification and validation
- Identify LE run-time and compilation issues in machine-readable format
- Identify incompatibilities in language usage
- Convert the incompatibilities in COBOL syntax to valid 1985 standard COBOL syntax
- Convert old CICS command syntax to the syntax required for current COBOL compilers.
A compiler migration may or may not require language syntax changes. Your inventory and assessment of that inventory will point you in the correct direction for this process. Unfortunately, the second sub-step of compiler migration, exploiting new functions, is often ignored. There are several good reasons to move to the new compilers besides the ability to work with the new CICS and DB2. You should try to understand these new features to take advantage of them.
No two LE assessments or migrations are identical because each customer has a different inventory of compilers, applications, and attributes. Most attribute and compiler information is best obtained from the load modules of production applications. Unfortunately, in some cases, this is the only reliable source for this information. IBM provides several z/OS tools that can help identify some of this information. You may have to use multiple tools to evaluate a single module. But, if reading hex dumps isn’t your cup of tea, you probably want to find other alternatives.
Ideally, to complete an assessment, you want a comprehensive set of flexible machine-readable records and straightforward exception and analysis reports that identify migration inhibitors in your production application inventory. These flexible machine-readable and report formats also should be able to be used as input to the tool you use to manage your source code changes and testing processes.
Mellon Financial, a global financial institution based in Pittsburgh, PA, migrated to LE using this process to minimize their resource requirements, reduce costs, and accelerate the completion of their LE migration project plan. It all began with a complete understanding of the inventory of languages, compilers, and attributes currently in use.
Shawn Klingensmith, a vice president in Mellon’s Technology Delivery Department, indicates that, “By combining output from source inventory tools (such as Micro Focus Revolve) with load module inventory tools (such as Edge Portfolio Analyzer), we were able to create a repeatable monitoring process that identifies:
- Where elements are used or embedded in other elements such as programs, JCL, and online transactions
- The compiler versions and compiler options used to create elements
- Obsolete and duplicate elements, which significantly reduced the conversion scope and inventory.
Once your inventory is completely validated, you can move forward in a comprehensive manner to ensure the integrity of your systems. Because you have a clear picture of the issues, you also can understand where a change in one area might impact other applications or parts of the same application. In some cases, this global view may point you to a more efficient approach to the migration. The typical approaches concentrate on a bottom-up migration, while starting with those areas that have the highest probability of success.
So far, the effort we’ve described has emphasized planning. Success hinges on a clear understanding of the work to be done.
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