P2M 202 · CALCULATE
Material Requirements Planning calculates what supply is needed, in what quantity, and by when.
MRP nets stock, receipts, reservations, sales demand, forecasts, safety stock, lead times, and lot-sizing rules to create proposals and exception messages.
HOW IT WORKS
MRP compares need, supply, and timing
MRP answers a practical planning question: given what we need and what we already expect to have, what are we short of and when? It compares requirements against available stock and expected receipts while considering timing. Where available supply is insufficient, SAP identifies the shortage and calculates additional supply requirements.
Concept flow: Demand + existing supply + timing → shortage → required supply. For manufactured products, BOM explosion can turn finished-product demand into dependent component demand.
CAPABILITY MODEL
Understand the input, decision, and result
Read the capability as a connected planning decision before moving into detailed SAP controls.
Requirements
Forecasts, orders, dependent demand, safety stock, and timing express what must be covered.
Available supply
Stock, scheduled receipts, reservations, and existing proposals show what is already available or expected.
Shortage and response
MRP identifies uncovered quantity and date, then creates the appropriate supply proposal.
OPERATIONAL FLOW
How the capability performs
The sequence connects business need to a planning or execution result.
Collect requirements
MRP reads the relevant demand and dates for the material and planning scope.
Compare supply and need
Stock and expected receipts are considered against requirements in time sequence.
Create lower-level need
For manufactured materials, the selected BOM translates the shortage into component requirements.
Expose the gap
The uncovered quantity and date become planned supply or an exception for planner review.
DESIGN & CONTROL
What shapes the result
These controls work together; a locally correct setting can still produce the wrong planning outcome.
Planning scope
MRP type, controller, plant, planning horizon, and time fence determine what the run considers.
Supply assumptions
Safety stock, lead times, lot sizing, procurement type, and existing receipts shape the shortage result.
Master-data integrity
Material, BOM, routing, and production version data determine whether the proposal represents feasible supply.
DIAGNOSTIC EVIDENCE
What proves the result?
Use the business input, system objects, and resulting state together.
Demand elements, quantities, dates, reservations, safety stock, and dependent requirements.
Unrestricted stock, scheduled receipts, firmed proposals, and pegging or coverage context.
Shortage, exception, planned order, purchase requisition, dates, quantities, and run evidence.
PLANNING MOMENT
Demand for 500 pumps arrives while stock and scheduled receipts cover only 320.
MRP exposes the remaining quantity and date, then creates supply proposals for the pump and its dependent components rather than pretending the original stock can cover the requirement.
- Shortage is dated
- Existing supply is visible
- Components are planned
- Proposal is reviewable
IN SAP
Simple representation
These are the main planning objects to recognize before moving into detailed controls.
Requirements · Stock · Scheduled receipts · Planned orders or purchase requisitions
How SAP controls it
MRP type, controller, lot size, procurement type, planning time fence, safety stock, lead times, and scope of planning drive the result.
Demand for 500 finished units creates planned orders for assembly and dependent requirements for components.
Connect this capability to the complete execution and integration story.