If you make things and you are outgrowing spreadsheets, someone will eventually tell you that you need an ERP. It is worth knowing what that word actually commits you to before you agree.
The short version
MRP plans and runs production. It answers what to make, what to buy, when, and what it cost. ERP does that too, and then adds finance, HR, payroll, CRM and whatever else the vendor has acquired.
ERP is not a better MRP. It is a wider system, and width has a price that is paid in implementation time, consultant days and the number of people who have to change how they work.
What each one actually covers
| Area | MRP | ERP |
|---|---|---|
| Bills of materials and routing | Yes | Yes |
| Material planning and purchasing | Yes | Yes |
| Works orders and shop floor | Yes | Usually, sometimes as a module |
| Stock and warehouse | Yes | Yes |
| Invoicing and accounts receivable | Often | Yes |
| General ledger and statutory accounts | No, integrates instead | Yes |
| Payroll and HR | No | Yes |
| Typical implementation | Weeks | Months to years |
When a workshop genuinely needs ERP
There are real cases. Be honest about whether you are in one.
- You run multiple legal entities, consolidate accounts across them, or report in more than one currency.
- You have an in-house finance team who need the ledger and the operations in one database rather than integrated.
- You are large enough that a dedicated implementation team and a six figure budget are normal, not frightening.
When you almost certainly do not
- You are under about fifty people and your accountant is happy in Xero or Sage.
- Your actual problem is that you do not know what stock you hold, what a job cost, or which batch went to which customer.
- Nobody in the building has time to run a twelve month project on top of their day job.
That last point sinks more ERP projects than any technical failing. The system is fine. The workshop simply never had the spare capacity to implement it.
Most UK workshops that think they need an ERP need production visibility, traceability and honest job costing. That is MRP, and it takes weeks rather than quarters.
The middle path most people actually want
Run MRP for the making, keep your accountant in the accounting package, and connect them. Brytebuild pushes invoices, bills and COGS journals into Xero or Sage, and pulls Xero payments back for reconciliation. Your accountant keeps the tool they know. You get the operational side you were missing.
We deliberately do not run an internal general ledger. Building a worse version of Xero would help nobody.
How to decide in an afternoon
- Write down the three things going wrong this month. If they are all production, stock or traceability, you want MRP.
- Ask your accountant whether the current accounting setup is a problem. If it is not, do not replace it.
- Ask who will run the implementation and when. If the answer is nobody and never, pick the smaller system.
If that lands on MRP, our feature list sets out exactly what is included at each plan, and the industry pages cover the problems we hear most often in each sector.