MRP vs ERP

MRP and ERP get used interchangeably by vendors, but they cover different scopes. Here's what each one actually does and when a standalone MRP is the right answer vs full ERP.

MRP — Material Requirements Planning

MRP, first formalized in the 1960s, answers a specific question: given demand forecasts, current stock, and bills of materials, what raw materials should we order and when?

A modern MRP tool typically handles:

• Bills of materials (BOMs), often multi-level
• Inventory tracking — raw, WIP, finished goods
• Demand forecasting (or import from sales orders)
• Production order generation and scheduling
• Purchase order generation based on the MRP run
• Sometimes: basic accounting integration to QuickBooks/Xero

Examples of standalone MRP software: MRPeasy, Katana, Fishbowl Manufacturing, Fulcrum.

ERP — Enterprise Resource Planning

ERP is the superset. MRP started in the 1960s as a manufacturing-specific concept; in the 1980s it expanded to MRP II (adding capacity and labor planning); by the 1990s the broader scope was rebranded as ERP and absorbed accounting, sales, HR, and procurement modules.

A full ERP includes everything MRP does plus:

• General-ledger accounting and financial statements
• Accounts payable / receivable
• Payroll and HR
• CRM and sales pipeline
• Multi-entity / multi-currency / multi-site
• Compliance, audit trails, regulatory reporting

Examples: SAP S/4HANA, Oracle NetSuite, Microsoft Dynamics 365, Epicor Kinetic, Infor CloudSuite.

When MRP is enough

For most small-to-mid manufacturers (20–250 employees) running QuickBooks or Xero for accounting, a standalone MRP tool covers the production-planning need at 10–20% of ERP cost. Typical MRP pricing runs $50–$200 per user per month vs ERP at $500+/user/mo plus a $30k–$80k year-one implementation.

When you actually need ERP

You need ERP when one of these is true: multi-site operations with complex inter-company accounting; regulatory reporting (public company, FDA, defense); 1000+ employees with HR needs that exceed your accounting software; or specific industry compliance (food traceability, pharma cGMP) that ERP vertical solutions are built for.

For everyone else, MRP + accounting software + a focused operational suite (like PF9) covers the same surface area for a fraction of the cost.