Implement Master Planning
Coverage and setup
Master planning starts with coverage groups (defaults) and item coverage (per item and warehouse). The coverage code drives behaviour: Manual never auto-replenishes, Period covers demand across a period, Min/Max replenishes up to maximum when projected on hand falls below minimum, and Requirement plans exact demand with lot-size rounding. Coverage settings include lead times, negative days (tolerance before a delay message), safety stock, safety margins and days of coverage.
Plans and runs
A static master plan uses a snapshot of data; a dynamic master plan always uses current data and is the usual choice for operational runs. The run generates planned orders (purchase, production, transfer, kanban) with action messages (advance, postpone, increase, decrease, cancel) and delay messages. Pegging shows which demand drives an order. You firm planned orders to protect them from recalculation, then convert them to real orders. Forecast models with a reduction key consume forecast against actual demand so demand is not counted twice.
Planning Optimization
The Planning Optimization service runs the MRP calculation outside the batch framework and is faster, but not every legacy capability is supported. Confirm feature coverage before recommending it in a scenario question.
Traps
- Confusing action messages (date or quantity changes on existing orders) with delay messages (demand cannot be met in time).
- Forgetting a forecast reduction key, so forecast and sales orders both drive demand.
- Assuming firming equals conversion - a firm planned order is still a planned order.
- Believing Min/Max orders by the shortfall; it orders up to the maximum.
Rule of thumb
Coverage code = trigger rule, lot size = order quantity, lead time = timing. If a scenario describes stock dipping below a threshold and replenishing to a target, the answer is Min/Max, not Requirement.