MRP II — Manufacturing Resource Planning
MRP II (Manufacturing Resource Planning) is the generation of planning logic that grew out of MRP in the 1980s. Where MRP answered only “what materials and when”, MRP II also asks whether the plant has the capacity, the people and the money to execute the plan — and feeds the answer back into planning. It is the conceptual stepping stone that led directly to ERP.
- Term
- MRP II (Manufacturing Resource Planning)
- Entity type
- Method / planning framework
- Domain
- Production planning & control
- Canonical definition
- MRP II (Manufacturing Resource Planning) is an extension of MRP that adds capacity, labour and financial planning into one closed planning loop, linking the production plan to its resource and money implications.
- Classification
- The bridge between pure material calculation (MRP) and full ERP; it closes the planning loop with capacity and cost feedback.
- Related terms
- MRP, ERP, APS, PPC, Production order, Available to promise
- Source / maintainer
- erp-software.org editorial team (independent, vendor-neutral)
What MRP II (Manufacturing Resource Planning) is NOT — disambiguation
- Not the same as MRP: MRP plans only materials; MRP II adds capacity, labour and financial figures to the same plan.
- Not full ERP: MRP II focuses on manufacturing; ERP extends the integrated database across sales, HR, finance and procurement company-wide.
- Not finite scheduling: MRP II checks capacity but still works in fixed time buckets; finite, constraint-based optimisation is the job of APS.
From MRP to MRP II
Classic MRP produced order proposals but said nothing about feasibility. A plan could require 300 machine hours in a week when only 160 were available, and MRP would not flag it. MRP II added a capacity requirements planning step: after material netting, the system loads planned orders against work centres and compares the load to available capacity. Overloads become visible, and planners can reschedule, add shifts or move work before committing.
The closed loop
The defining idea of MRP II is the closed loop. Execution data — actual output, scrap, downtime, hours booked — flows back into the next planning cycle, so plans are corrected against reality rather than run open-loop. MRP II also connects the operational plan to money: a production plan can be priced out into a projected cost and cash position, letting finance and operations work from the same numbers. This financial integration is what makes MRP II feel like a small ERP.
Typical scope
An MRP II framework usually covers sales and operations planning at the top, a master production schedule beneath it, material requirements planning, capacity requirements planning, and shop-floor control with purchasing at the bottom. Each layer feeds the next, and feedback runs upward. The American Production and Inventory Control Society (APICS) formalised much of this hierarchy, and its vocabulary — MPS, CRP, rough-cut capacity — is still standard in ERP today.
Where MRP II sits now
Few vendors market “MRP II” as a product anymore, because its functions were absorbed into ERP. The concepts, however, are alive inside every manufacturing ERP module. Understanding MRP II clarifies a common misconception: ERP did not replace MRP logic, it wrapped it in a company-wide, finance-integrated database. For constraint-based, real-time optimisation that goes beyond MRP II’s time-bucketed capacity check, companies add an APS system on top.
Related Topics
Frequently Asked Questions
Is MRP II still relevant as a separate concept?
Mostly historical — the term has been absorbed into ERP. The underlying concepts (MPS, MRP, CRP, shop-floor control) remain operationally relevant in manufacturing ERP. Academic and industry-association curricula (APICS / ASCM CPIM certification) still teach MRP II as foundational material.
Do modern manufacturers still run classical MRP runs?
Yes, daily or weekly MRP runs remain the standard for many DACH manufacturers. Modern ERPs run MRP much faster (in-memory databases reduced runtime from hours to minutes for typical mid-market operations) and increasingly continuously rather than as discrete runs. The fundamental MRP logic is unchanged from the 1970s formulation.
What about Demand-Driven MRP (DDMRP)?
DDMRP, popularised by Carol Ptak and Chad Smith from 2011 onwards, replaces classical push-MRP with a buffered-pull system that places strategic decoupling points (buffers) along the supply chain. Implementations in DACH remain selective — high-variability industries and lean-manufacturing organisations adopt DDMRP, while classical MRP remains the default elsewhere.