MRP vs. ERP — Difference and Distinction
MRP (Material Requirements Planning) and ERP (Enterprise Resource Planning) are often confused. In short: MRP plans only material and production, while ERP integrates every business area from purchasing and finance to sales. Historically MRP is the direct predecessor of ERP — and today sits as a core module inside every ERP system.
What is MRP?
MRP answers one central question: which material is needed, when and in what quantity? From primary demand (customer orders, sales plan), bills of materials and stock levels, MRP automatically calculates purchase and production proposals.
- Requirements explosion: from the finished product down to the screw
- Net requirements: gross demand minus available stock and open orders
- Scheduling: backward from the delivery date over lead times
The extension MRP II added capacity and resource planning in the early 1980s.
What is ERP?
ERP is the evolution of MRP II into a company-wide complete solution. It integrates material and production planning with finance, controlling, HR, sales, purchasing and CRM on a single data basis — the single point of truth.
While MRP is a function, ERP is an architecture: all departments work on the same master data, and postings cascade across departments (a goods-receipt posting raises stock and books the liability).
MRP vs. ERP at a glance
| Criterion | MRP | ERP |
|---|---|---|
| Focus | material and production planning | the whole company |
| Modules | requirements planning, scheduling | finance, controlling, HR, sales, purchasing, production and more |
| Data basis | material and order data | integrated company database |
| History | predecessor (1960s–80s) | evolution (from 1990s) |
Rule of thumb: MRP is today a module within the ERP, not a competing standalone system.
Related topics
- MRP — Material Requirements Planning
- MRP II
- ERP — Enterprise Resource Planning
- Material Planning
- PPS — Production Planning & Control
Frequently Asked Questions
What is the difference between MRP and ERP?
MRP plans only material and production requirements. ERP integrates that planning with finance, controlling, HR, sales and purchasing on a single data basis. MRP is today a module within the ERP.
Is MRP part of ERP?
Yes. Material requirements planning (MRP) and capacity planning (MRP II) are core modules in virtually every ERP system. ERP is the company-wide evolution of MRP II.
Which came first, MRP or ERP?
MRP came first. It emerged in the 1960s, was extended to MRP II in the 1980s (adding capacity planning) and grew into ERP from the 1990s, integrating all business areas.
Does a small manufacturer need ERP or is MRP enough?
If only production planning needs digitising and accounting/sales run well separately, an MRP tool can suffice. Once double data entry between departments costs time, an integrated ERP pays off.
What does MRP II mean?
MRP II (Manufacturing Resource Planning) extends classic MRP with capacity, resource and partly financial planning. It bridges pure material requirements planning and today's ERP.