What is an ERP system? Modules, an example and ERP vs CRM
What is an ERP system? A plain definition, the modules it joins, one order traced with and without ERP, ERP vs CRM, and when a small business needs one.
An ERP system (enterprise resource planning) is business software that keeps finance, purchasing, stock, sales, production and HR in one shared database. You enter an order once, and the invoice, stock count, warehouse task and accounts all update from that one record.
Quick answer
- Modules: finance, purchasing, inventory and warehouse, sales, production, HR and payroll.
- CRM manages customers and sales; ERP manages what follows the sale.
- In 2025, 46.45% of EU enterprises with 10+ employees used ERP, but only 21.89% in Croatia (Eurostat).
- You need one when the same data is retyped in several places daily.
One order travelling through the company
Follow one web-shop order for 20 boxes:
- Sales - the order lands with customer, prices and discount.
- Inventory - 20 boxes are reserved so nobody sells them twice.
- Warehouse - a picking list and shipping label are created.
- Purchasing - stock falls below minimum, so a purchase proposal is raised.
- Finance - the invoice is issued and the payment matched.
- Production and HR - materials and hours are booked to the job.
Without ERP, each step lives in a separate program.
A worked example: a small distributor
An illustrative example, not client data: a distributor gets 25 web-shop orders a day. Each order is retyped into the invoicing program (2 min), the stock spreadsheet (2 min), an email to the warehouse (1 min) and the courier portal (1 min): 6 minutes per order.
25 orders × 6 min = 150 minutes a day. Over 21 working days that is about 52 hours a month of copying, plus typos that ship the wrong item.
With the shop connected to an ERP, order, reservation, invoice draft and label are created automatically. Checking exceptions takes about a minute per order: roughly 9 hours a month. The 43 hours saved are more than a working week, every month.
ERP vs CRM: what is the difference?
| ERP | CRM | |
|---|---|---|
| Who uses it | accounting, warehouse, purchasing, production | sales, marketing, support |
| Main data | stock, orders, invoices, costs, payroll | leads, contacts, deals, conversations |
| When you need it | operations are retyped between tools | leads and follow-ups slip through the cracks |
CRM wins the customer, ERP fulfils and invoices. Eurostat puts EU CRM use at 28.51% in 2025. Many companies need both.
Does a small business need ERP yet?
Signs you do: the same order is typed into three or more places, nobody trusts the stock figure, month-end means days of reconciling, or you sell on several channels from one stock.
Signs you don’t: a few orders a day. Then accounting software plus a web shop plus one good integration often removes most of the copying, and a small internal tool can cover the odd process (see custom software vs SaaS). ERP means new processes, migration and training, not just a licence.
When you outgrow it, read about costs and ERP integrations. Our Strategy & Audit and Automation services start by mapping where your data is retyped today.
Frequently Asked Questions
Is ERP only for large companies? No. 41.08% of small EU enterprises (10-49 employees) used ERP in 2025 (Eurostat).
What is a modular ERP? You start with the modules you need, such as finance and inventory, and add others later without switching systems.
Related Articles
- How to connect a web shop to ERP: orders, stock, prices
- CRM, ERP and internal tools: how much does digitalisation cost?
- ERP integrations: SAP, Dynamics and Pantheon
Thinking about ERP for your company?
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