You have maintained the parameters for simple discontinuation in the material master of a component.

Simple discontinuation in SAP S/4HANA (material master, MRP 4 view, fields: Discontinuation Indicator, Effective-Out Date, Follow-Up Material) replaces a discontinued component with a follow-up material when stock is depleted. If the available stock is zero and the discontinuation date is in the past:

Material requirements planning(C): MRP (MD01/MD02) is affected because it checks the discontinuation settings. When stock is zero and the effective-out date has passed, MRP stops generating requirements for the discontinued material and creates them for the follow-up material instead (visible in MD04). This ensures planning continuity with the replacement.

Backflushing(A) (e.g., during CO11N) uses existing stock or reservations, not directly impacted by discontinuation unless stock is unavailable—but it’s a downstream process.Kanban(B) relies on replenishment triggers, not discontinuation logic, though stock-outs could disrupt it indirectly.Production order release(D) (CO02) checks material availability, but discontinuation is handled in MRP, not at release. This is per SAP’s discontinuation process.