Inventory age for stock migrated from legacy SAP R/3 system

Dear S4HC Customer Community & Experts,

We have a bank requirement to produce a weekly inventory age report. When we migrate our inventory to S4HC, we need a way to keep track of the age of the inventory. For example, if we have 100 units of material ABC at the time we cut over to S4HC, we need to know that 20 units were received 6-9 months ago, 30 units were received 4-6 months ago, and the remaining 50 units were received less that 1 month ago.

Our team has looked at the Inventory Balance and Warehouse Stock migration objects and there are limitations with back-dating the document date. The Inventory Balance object generates an inbound delivery (not a material document). While the inbound delivery shows the back-dated document date, when we post the GR, the material document shows the document date as the current date. The Warehouse stock object does reflect a back dated warehouse received date in WM, but the material document shows current date. We are not sure whether the WHS received date can be used for inventory age via an app or a KPI.

Any information you can provide on this topic is much appreciated.