How are organizations "charging" back hours to an IT system? Our organization organized resources into work team based on system they support. As an example, System A would have 5 employees dedicated to maintaining and enhancing the system. When a project comes along that requires work on System A (along with other systems), the system resources are assigned to a task within that project. How are other companies tracking these effort hours to a their respective system? Here's are options that I have contemplated and why they don't seem to work:
1. Create a system OBS to identify the resource "home" system. When actual hours is submitted, I can then group all resource hours by this System OBS to see the "chargeback" by each system. Problem here is that resources can be lent to work on other systems. So even though I belong to System A, I may work on system B (potentially within the same project) and all my hours working on System B should be charge to that system.
2. Use resource financial attributes such as Resource Class or Transaction Class. The issue here is that our systems are hierarchical. For example System A and System B could be a child of System C.
Any suggestion or insight would be appreciated.