Change to Availability Calculation in Item Class

We set up two Availability Calculations - one which included Qty on Production Supply (WithRO) and one which excluded Qty on Production Supply (WithoutRO). An Item Class was assigned "WithoutRO" and after a few months it was determined that "WithRO" would be better for this Item Class. The Item Class was updated to the new Availability Calculation. The "Available" quantity on the Inventory Summary doesn't update initially, however the Available Quantity on the Allocation Details is updated based on the new availability rule. Is there a delay in this update and if so how do I know how long before the change is implemented in all places?