Why is Worker Position-Period Activity Taking precedence over the costing allocation I had set up?

Workday follows a costing allocation hierarchy.  If an employee is receiving pay through a Period Activity Pay, this takes precedence over any other costing allocations that may be set up for that worker (Ex. A Worker Position costing allocation).  This gives the opportunity to enter costing overrides on the Period Activity Pay for how you want that pay to be charged.  If no costing override is entered on the Period Activity Pay, the Worker Position costing allocation will be used.  If the Costing Override has been entered but needs to be changed, refer to the instructions on Editing a Period Activity Pay.