Approvals Triage: Uniqueness of Department and Cost Center necessary for approvals to work correctly

Summary

Why are my approvals getting routed to an incorrect approval hierarchy / manager?

Content

Customers  / Support

This is one area of triage that we seem to encounter on a very regular basis. 

Problem:

Business created a requisition for Department 123 whose manager is XYZ. When the requisition is submitted for approval it goes to a completely different approver hierarchy belonging to manager DEF. 

Triage and Conclusion:

On detailed triage, development realized that the same cost center has been reused in configuring more than one department. I am referring to the Department definition where a Cost Center is associated with the department. For approval rules to work,