IBM Business Process Manager - customising the configuration

Having become recently and intimately acquainted with IBM BPM, it's taken me a little while to become accustomed to the various configuration files that BPM uses.

Thankfully, this IBM Technote: -

Configuration file overview and explanation for Lombardi Teamworks, WebSphere Lombardi Edition (WLE), and the IBM Business Process Manager (BPM) products

has been of immense use, and has validated something that Neil Kolban also says with regard to which file to amend: -

Using the 100Custom.xml file to add new configuration values or replace existing values

The 100Custom.xml file is designed to hold the customization and changes that you want to make to any of the configuration files. The idea is that if you do a fresh installation of a new version, you can simply drop in your existing 100Custom.xml file and all the changes that you have made will be picked up and used instead of the default values. Ask yourself, if I have to reinstall the product, what would I need to change in the configuration files? Those changes are the things that you want to put in the 100Custom.xml file.

Neil puts it even more succinctly: -

It is strongly recommended not to edit the content of the 99Local.xml file. Instead, edit the 100Custom.xml file and add/replace all changes there. When Process Server starts, it will merge the 99Local.xml with the 100Custom.xml producing a combined result. Editing only 100Custom.xml keeps all the changes in one place and aids in maintainability. Changes made to these configuration files don't take effect until after the next restart of the Process Server.

Simple, 100Custom.xml is your friend.