What is MRP II (Manufacturing Resource Planning)?
An expanded planning method that extends material requirements planning to coordinate labor, machine capacity, and financials across the whole manufacturing operation.
Definition
MRP II (Manufacturing Resource Planning) evolved in the 1980s from material requirements planning (MRP) to address its biggest weakness: MRP planned materials but ignored whether the plant actually had the capacity, labor, and money to execute the plan. MRP II adds capacity planning, shop floor control, demand forecasting, and a financial feedback loop so that operational plans tie directly to the general ledger and budgets. It introduced the idea of a single, integrated plan flowing from sales and operations planning (S&OP) down through the master production schedule, MRP, and capacity requirements planning. MRP II is widely regarded as the conceptual ancestor of modern ERP, which broadened the same closed-loop logic to cover the entire enterprise.
How MRP II Works in ERP
In an ERP system, MRP II is not a separate module but the integrated logic connecting demand planning, master scheduling, the MRP run, capacity planning, and finance. When a production plan is generated, the ERP simultaneously checks material availability, work center capacity, and the cost impact, posting projected labor and overhead to financial forecasts. This closed loop lets planners run what-if scenarios and see both the operational and monetary consequences before committing.
ERP Vendors with Strong MRP II
Frequently Asked Questions
What is the difference between MRP and MRP II?
MRP (material requirements planning) calculates what materials to order and when, based on the bill of materials and demand. MRP II expands that to include capacity, labor, scheduling, and financial planning, closing the loop so plans are validated against real plant resources. In short, MRP plans materials while MRP II plans the entire manufacturing resource base. Most modern ERP systems implement MRP II logic by default.
Is MRP II still relevant if I have a modern ERP?
Yes, because nearly every manufacturing ERP is built on MRP II principles even if the term is rarely used in marketing. Understanding MRP II helps you evaluate whether a system genuinely closes the loop between planning, capacity, and finance, or only handles materials. When comparing vendors, ask how the master schedule, capacity check, and cost roll-up interact, which is the core MRP II question.