One of the more surprisingly useful things that can be done in a Groovy calculation is querying metadata. This was discussed in Part 11: Accessing Metadata Properties, but I recently had a situation where users could load data at parent levels and have it allocated down to the bottom of the hierarchies.
Now that you are knee deep in Groovy, help yourself out and reuse common code. The more you learn, the more efficient you will be and will laugh at some of your initial attempts at your Groovy calculations. If you are like me, you get excited about all the possibilities and learn as you go. When you find better ways to do something, or even preferable ways, you end up with an application with inconsistent representations of the same logic. You are too busy to go back and update all the snippets you have improved, so it stays in a somewhat messy state.
Do yourself a favor and start reusing some of the things you need in every script.
When automating Business Rules through batch scripts, an XML file is needed to state the runtime prompts. This is how the batch script will know which members to run the business rule for. Is there an easy way to create these files?