DRP (Distribution Requirements Planning): Definition, Formula & Examples
Distribution Requirements Planning (DRP) is a system for planning when, where, and how much inventory to move across a distribution network. It takes demand signals from each stocking location — regional DCs, branch warehouses, retail points — and works backwards through the supply chain to determine transfer and replenishment orders before demand arrives.
For food distributors and manufacturers with multi-location operations, DRP is what prevents the common failure mode of having the right total inventory but the wrong mix of stock at each location. This guide covers how DRP works, how it compares to MRP and other planning systems, and how food companies apply it in practice.
DRP vs. MRP vs. demand planning: what each system does
| System | Focus | Driven by | Output |
|---|---|---|---|
| MRP (Material Requirements Planning) | Factory: what to make and buy | Production schedule + bill of materials | Purchase orders, production orders |
| DRP (Distribution Requirements Planning) | Distribution: what to move and where | Customer demand at each location | Transfer orders, replenishment orders |
| DRP II (Distribution Resource Planning) | Distribution + transport capacity | DRP + truck capacity and route constraints | Optimized routing + fleet planning |
| Demand Planning | Forecasting: what will be needed | Historical data + market signals | Demand forecasts (input to DRP and MRP) |
| S&OP (Sales & Operations Planning) | Business alignment: matching supply and demand | Commercial plans + supply capacity | Agreed volume plan across sales, supply chain, and finance |
MRP and DRP often work together: MRP calculates what a factory needs to produce, DRP calculates what the distribution network needs to receive from that factory and how to spread inventory across locations.
How DRP calculates replenishment: the core logic
DRP applies the same netting logic as MRP, but at the distribution level. For each item at each location, the calculation works as follows:
- Gross requirements — demand forecast plus open customer orders at this location for the period
- Scheduled receipts — incoming transfers or purchase orders already in progress
- Projected on-hand — current stock minus gross requirements, plus scheduled receipts
- Net requirements — when projected on-hand falls below safety stock, a replenishment is needed
- Planned orders — the transfer from another DC or purchase from supplier to cover the net requirement, timed to arrive before the stockout occurs
The planned orders at each DC roll up to become demand signals at the supplying location — which feeds back into MRP at the factory or becomes purchase orders to suppliers. This upstream-downstream connection is what makes DRP a network-wide planning system rather than a location-by-location reorder system.
DRP in food distribution: a practical example
A regional seafood distributor operates three DCs: one in Boston, one in Miami, and one in Seattle. Each DC services different customer segments with partially overlapping SKUs.
Without DRP, each DC manager reorders independently based on local stock levels. In practice, Boston runs out of wild salmon while Miami has four weeks of surplus. The company has the inventory, but it is in the wrong place.
With DRP, the planning system sees demand signals from all three locations simultaneously, calculates when each location will go below safety stock, and generates transfer orders from Miami to Boston before the stockout. The central supply order from the fishing supplier is also optimized — ordered once at scale rather than three separate partial orders.
Food-specific DRP considerations
Perishability and shelf life
DRP for food must account for expiration dates when calculating projected on-hand. A standard DRP calculation that ignores lot expiry will show adequate projected inventory even when the stock on hand will expire before the demand arrives. FEFO (First Expired, First Out) logic must be built into the planning engine.
Catch weight and variable yield
Seafood and meat DCs frequently deal with items where the received quantity varies from the ordered quantity. DRP systems for these verticals need to plan in weight-based units, not just pieces, and handle the discrepancy between ordered weight and received weight without manual adjustment.
Lot attributes and customer specifications
In food distribution, inventory is not fungible. A customer may accept only a specific size range, origin, or grade. DRP in food needs to plan not just "how much salmon" but "how much wild Norwegian salmon, 6–8 lb trim" at each location — which requires lot attribute tracking integrated into the planning logic.
How inecta Food ERP supports distribution requirements planning
inecta Food ERP, built on Microsoft Dynamics 365 Business Central, provides integrated DRP capabilities for multi-location food distribution:
- Item Availability by Location — real-time visibility into stock levels, scheduled receipts, gross requirements, and projected inventory balances at each DC, with lot attribute filtering
- Logistics per Order Management — orchestrates route assignment, shipping agent assignment, and warehouse shipment creation across locations; handles transfer order generation for inter-DC stock movements
- Logistic Buffer Management — aggregates sales, purchase, and transfer orders into a unified transportation planning view, enabling consolidated shipments across order types
- Truck Routes and Customer Route Assignment — links customer locations to weekly delivery routes by DC, feeding route-based demand signals back into the replenishment plan
For warehouse operations and food distributors managing multi-location networks, having DRP integrated with the warehouse management and sales order system eliminates the data reconciliation that standalone DRP tools require.
Frequently asked questions
What does DRP stand for in supply chain?
DRP stands for Distribution Requirements Planning. It is a system for planning inventory replenishment across a distribution network — determining when, where, and how much inventory to move between facilities to meet demand at each location before stockouts occur.
What is the difference between DRP and MRP?
MRP (Material Requirements Planning) works at the factory level — it calculates what raw materials and components are needed to meet a production schedule, working backwards from the production plan through the bill of materials. DRP works at the distribution level — it calculates what finished goods need to move between distribution centers to meet customer demand at each location. In practice, DRP demand rolls up to become supply requirements that feed into MRP or supplier purchase orders.
What is DRP II?
DRP II (Distribution Resource Planning) extends DRP by adding transportation capacity constraints to the planning calculation. While DRP determines what needs to move and when, DRP II also accounts for truck capacity, route frequencies, and freight costs to generate a transportation plan that is both inventory-optimal and logistically feasible.
How does DRP work in food distribution?
DRP in food distribution calculates projected stock levels at each distribution center, identifies when and where inventory will fall below safety stock thresholds, and generates transfer or replenishment orders in advance. Food-specific DRP must also account for lot expiry dates, catch weight variability, and lot attribute specifications that affect which inventory satisfies which customer demand.
What are the benefits of distribution requirements planning?
The primary benefits are: reducing stockouts at individual locations while avoiding network-wide overstock, improving OTIF (On-Time In-Full) performance by ensuring the right product is at the right DC before it is needed, reducing emergency freight costs caused by reactive stock transfers, and improving purchase order consolidation through better visibility into network-wide demand.