MRP vs ERP: the actual difference (and which a small shop needs)
MRP plans materials and production. ERP wraps that core in accounting, HR, and everything else. Here's the difference in practice — and the honest answer for small shops.
MRP plans the making of things: materials, BOMs, work orders, purchasing. ERP (enterprise resource planning) wraps that manufacturing core in everything else a company runs — accounting, HR, CRM, payroll — as one integrated suite. Every ERP contains an MRP somewhere inside it. Almost no MRP tries to be an ERP.
The practical difference
| MRP | ERP | |
|---|---|---|
| Answers | What to buy and make, and when | How the whole business runs |
| Scope | Inventory, BOMs, work orders, purchasing | That, plus finance, HR, CRM, payroll… |
| Typical rollout | Days to weeks | 6–18 months, often with consultants |
| Who runs it daily | The shop | Every department |
| Failure mode | Stale inventory data | Abandoned modules and change-order invoices |
Why the distinction gets muddy
Vendors blur it on purpose. Mid-market “manufacturing ERP” packages are often an MRP core plus an accounting module and a big price tag. Meanwhile some cloud MRPs quietly add invoicing until they’re ERP-shaped. Ignore the label and ask one question: which departments will live in this software? If the answer is “the shop,” you’re shopping for MRP. If the answer is “all of them,” you’re shopping for ERP — and for an implementation project.
The honest answer for small shops
Most shops under ~50 people already have an ERP; it’s called QuickBooks plus the shop system. Accounting tools are excellent at money and terrible at materials; MRP is the reverse. Pairing a light MRP like TrackFinch with the accounting you already use gets you 90% of an ERP’s value at roughly none of its rollout cost.
The cases where a real ERP earns its keep: multi-entity finance, regulated industries with audit-integrated workflows, or headcount where department-to-department handoffs are the bottleneck. Those are real — and they’re rarely a 12-person fab shop’s problems.
Signs you’re being oversold
- The demo spends more time on dashboards than on how a work order gets released
- “Implementation partner” appears before you’ve seen a price
- The floor-facing screens require a mouse
- You’re asked to map your processes before you’re allowed to touch the product
A shop system should be provable in an afternoon with your own data. That’s the test — run it on a free trial with your real BOMs, not a sales deck.
The one-sentence version: MRP runs the shop; ERP runs the company; a small shop usually needs the first and already owns a good-enough version of the second.