It's probably wise to point your customer to IBM's own words. Here's what
IBM says in Chapter 1 ("Do I need to recompile?") of the Enterprise PL/I
for z/OS Version 4.4 Compiler and Run-Time Migration Guide. The current (as
I write this), direct link to that publication is here:http://publibfp.boulder.ibm.com/epubs/pdf/ibm4mg03.pdf This link is subject to change of course. "Ideally, programs should be compiled with IBM Enterprise PL/I for z/OS and run with the supported run-time library (Language Environment). You can reach this ideal state gradually, by starting with a run-time migration followed by a compiler migration." Later in the same publication IBM offers this bit of advice (after restating its recommendation to move toward the ideal state): "Compiler migration can be done all at once or by separate execution units. How to divide up your PL/I source into separate execution units is described in 'Partitioning PL/I source programs into units of execution' on page 134. If you decide to mix old PL/I modules with Enterprise PL/I modules, there are limited circumstances in which this mix will work. These limitations are described in 'Object and load module considerations' on page 131." To net it out, there are three basic migration choices (after run-time migration): 1. Recompile everything all at once; 2. Recompile by separate execution units; 3. Recompile gradually, mixing "old" PL/I modules with Enterprise PL/I modules carefully in only IBM's documented ways. In my experience most customers migrating from PL/I for MVS to Enterprise PL/I do not recompile every program in their inventory all at once (option #1), though of course that's certainly possible and admirable. They usually select option #2, option #3, or some combination of those two options, e.g. recompiling by separate execution units within particular applications or LPARs, mixing modules carefully in others. -------------------------------------------------------------------------------------------------------- Timothy Sipples IT Architect Executive, zEnterprise Industry Solutions, AP/GCG/MEA -------------------------------------------------------------------------------------------------------- E-Mail: [email protected] ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
