[AndrewDMcG]

YES! No system is harder to maintain than one that consists of a huge mesh of configuration files. No kidding, I have worked on a large company-wide reporting system where the easiest changes to make were to the code. Code changes could be made, tested and released in a fairly straightforward way. The harder things to change were to configuration files (Spring, things like that). Because they had global effect, and contained elements that were specific to a dev/test/production environment, making and deploying changes to one were more difficult. But the very hardest things to make changes in were the report and process parameters stored in the database. They were impossible to isolate the effects of since we had no easy way to trace to what functions they might affect, and were generally treated as immutable legacy that you worked around changing rather than touch. (I wouldn't claim this was a good system)

When you put something in a configuration file, you need to define who is going to change it, and how they are going to test their change. Otherwise you're in danger of muddling together different levels of abstraction, and breaking encapsulation all over the place.