What Is MRP? The Meaning of Material Requirements Planning Today

MRP stands for "Material Requirements Planning," but in practice it is much more than that. Modern MRP is a chain that runs from the sales order to the recipe, from the recipe to a stock comparison, and from there to a purchase suggestion. Set up correctly, it structurally ends the "we're out of material" crisis.

01. The Difference Between MRP and Classic ERP

Most classic ERPs claim an MRP function on paper but fall short in a real production environment. The main differences:

• Multi-level recipe support
• Alternative-material logic
• Capacity-based planning
• Shift and machine loading
• Standard-versus-actual variance analysis

If your ERP doesn't adequately support at least three of these five, you may need an MRP module that sits on top of it.

02. Recipe (BOM) Management Is Critical

The heart of MRP is the product recipe (Bill of Materials). A well-designed BOM:

• Works multi-level (semi-finished → raw material)
• Allows alternative-material definitions
• Has version control (when the recipe changes, past production remains accessible)
• Defines level-based scrap and cost

A wrong BOM produces a result that not even a correct MRP can manufacture.

03. Capacity Planning and Bottlenecks

Once the recipe side is validated, the capacity side comes into play. Which line, which shift, which operator can it run with? If these are defined in the system, MRP suggests a sound deadline for the order because — even when materials are sufficient — capacity may not be.

An MRP without capacity planning produces a plan that is mathematically correct but out of sync with reality.

04. Scrap and Efficiency Tracking

Production is planned, but it doesn't go as planned. Scrap and downtime records feed the learning side of MRP.

• Standard scrap vs actual scrap variance
• Scrap distribution by operator, shift and machine
• Downtime reasons (breakdown, material, quality)

This data makes the next planning cycle more realistic. An MRP without scrap records can manufacture correctly in its first month but starts to degrade by the third.