Calculate MPS planned production by combining forecast, customer orders, inventory, and scheduled receipts. Drive material and capacity plans.
The Master Production Schedule (MPS) is the primary driver of manufacturing activity. It translates demand (from forecasts and customer orders) into a production plan that specifies what to produce, how much, and when. The MPS bridges sales planning and shop floor execution.
The core calculation is: Planned Production = max(Forecast, Customer Orders) − On-Hand Inventory − Scheduled Receipts. When projected on-hand inventory drops below zero, a planned production order is triggered to bring it back to the target level.
This calculator performs a simplified single-period MPS calculation showing gross requirements, available inventory, net requirements, and planned production. It is essential for anyone learning MPS logic or doing quick planning calculations before entering data into an ERP system.
Tracking this metric consistently enables manufacturing teams to identify performance trends early and take corrective action before minor inefficiencies escalate into significant production losses. This measurement forms a critical foundation for capacity planning, helping teams align production capabilities with demand forecasts and strategic business objectives throughout the planning cycle.
The MPS is the plan that drives MRP, capacity planning, and purchasing. Getting it right means materials arrive on time, capacity is available, and customers get what they ordered when they need it. Precise quantification supports benchmarking against industry standards and internal targets, driving accountability and continuous improvement throughout the organization.
Gross Requirement = max(Forecast, Customer Orders) Projected On-Hand = On-Hand + Receipts − Gross Requirement If Projected < 0: Net Requirement = |Projected| Planned Production = roundUp(Net Requirement / Lot Size) × Lot Size
Result: Planned production = 200 units
Gross requirement = max(200, 180) = 200. Projected on-hand = 50 + 30 − 200 = −120. Net requirement = 120. Rounded up to lot size of 100 = 200 units planned production.
Make-to-stock (MTS) environments use MPS driven by forecasts. Make-to-order (MTO) environments use MPS driven by actual orders. Assemble-to-order (ATO) environments may MPS components to forecast and final assembly to order. The MPS logic adapts to each strategy.
An MPS that exceeds available capacity is useless. After generating the MPS, validate it against rough-cut capacity to confirm feasibility. If it overloads key work centers, adjust quantities or timing before releasing to MRP.
Time fences divide the planning horizon into zones with different change rules. The frozen zone allows minimal changes. The slushy zone allows changes with approval. The liquid zone allows free changes. This structure balances responsiveness with shop floor stability.
MPS plans finished goods production based on demand. MRP explodes the MPS through the bill of materials to plan component and raw material requirements. MPS drives MRP.
The frozen zone is a near-term period (often 1-4 weeks) where the MPS is locked and changes are restricted. This gives the shop floor stability and prevents constant plan changes that disrupt execution.
Using the maximum avoids double-counting. Customer orders are expected to consume the forecast. Taking the max means you plan for whichever is higher — actual orders if they exceed forecast, or forecast if orders haven't materialized yet.
Safety stock acts as a floor for projected on-hand. If projected inventory would drop below safety stock, a planned production order is triggered to restore the buffer. Add safety stock to the net requirement calculation.
At minimum, the MPS should cover the cumulative lead time for the product (including purchased material lead time). Typically, MPS horizons are 12-26 weeks for make-to-stock environments.
ATP is the quantity of finished goods that sales can commit to customers. It is the MPS quantity minus customer orders already booked. ATP helps sales make reliable delivery promises.