ERP system
Business management software that connects finance, purchasing, stock, sales, production and other company functions in one database.
What is ERP system?
ERP (Enterprise Resource Planning) is business management software that connects a company's core functions in one shared database: accounting and finance, purchasing, stock, sales and invoicing, production, HR and payroll. An order entered by sales flows into the warehouse, production and accounting without retyping, and everyone works with the same numbers. In short, an ERP system is a single source of truth about what a company buys, makes, sells and what it costs.
Why It Matters
Without ERP, data sits in accounting software, the online store, spreadsheets and email. The same records are retyped, stock levels do not match reality and management waits until month-end for figures. An ERP system removes double entry, speeds up order processing and shows margin, stock and cash flow in real time. It is also one of the largest IT investments a mid-sized company makes, so choosing and implementing ERP decides whether it pays back or disrupts operations.
Real-World Examples
- 1An online store passes orders to the ERP, which reserves stock, issues the invoice and posts it to the ledger.
- 2A manufacturer plans materials in the ERP by job and sees when components need to be ordered.
- 3A wholesaler keeps individual B2B price lists and credit limits for each customer in the ERP.
- 4Management tracks margin per job and receivables in one view instead of five spreadsheets.
What ERP stands for and where it came from
ERP stands for Enterprise Resource Planning. According to available sources, the term was coined by the research firm Gartner around 1990. It built on MRP (Material Requirements Planning) systems from the 1960s, which planned materials and inventory in manufacturing, and MRP II from the 1980s, which added capacity planning and production control.
ERP extended these manufacturing systems to the whole company. Today's ERP often runs in the cloud and connects through an API to the online store, CRM, bank or reporting tools.
What an ERP system consists of
ERP is modular: a company switches on only the functions it needs and adds more later. Typical modules:
- Finance and accounting: general ledger, receivables and payables, bank, VAT, fixed assets.
- Purchasing and stock: purchase orders, goods in and out, stocktakes, multiple warehouses and batches.
- Sales and invoicing: quotes, orders, price lists, discounts, invoices and credit notes.
- Production: bills of materials, material and capacity planning, work orders.
- HR and payroll: employees, attendance, payroll and contributions.
- Reporting: margin, cash flow and KPI dashboards across departments.
Some ERP systems also include CRM, service, project management or document management. The main difference from a set of separate tools is one database: data is entered once and is valid everywhere.
ERP vs CRM vs accounting software
Accounting software mainly handles bookkeeping, invoicing and tax. ERP adds stock, purchasing, production and process management across the company. CRM focuses on customers, enquiries and the sales pipeline, i.e. what happens before an order. We cover choosing and rolling out a CRM in CRM system for business.
In practice the systems work together: sales works in the CRM, a won deal is passed to the ERP, and the ERP ships, invoices and posts it. What matters is that the systems exchange data automatically rather than via manual exports.
When a business needs an ERP system
ERP makes sense when two or more of these apply:
- You retype the same data (orders, customers, stock) between the online store, warehouse and accounting.
- System stock levels do not match reality and you sell goods you no longer have.
- You run several warehouses, sales channels or branches and are losing track.
- You manufacture or assemble and plan materials in a spreadsheet.
- You only know margin per job or product after month-end close, if at all.
A sole trader or small service business without stock usually does fine with invoicing or accounting software and a few automations. For them ERP is unnecessarily expensive and complex.
Types of ERP and systems on the market
- Cloud ERP ([SaaS](/glossary/saas)): a monthly subscription per user; the vendor runs servers and updates. Faster start, lower upfront cost.
- On-premise ERP: a one-off licence running on your own infrastructure. More control, but you handle administration and backups.
- Open source ERP: for example, Odoo Community is available under an open source licence; you mainly pay for implementation and support. More on the model under Open Source.
Widely used international systems include SAP, Microsoft Dynamics 365 Business Central and Odoo; in Central Europe there are also local systems such as Helios (Asseco Solutions), ABRA Gen or Money and Vario (Seyfor). The brand matters less than how well the system covers your process, what API it offers and who will implement and support it.
How ERP implementation works
- Process analysis: describe how orders, goods and documents flow today and where errors occur. The output is a requirements brief, not a feature list.
- Choosing the system and partner: compare 2–3 options on your real scenarios, including licence and implementation cost over three years.
- Configuration and integrations: code lists, price lists, warehouses, connecting the online store, bank and other systems.
- Data migration: cleaning and transferring customers, products, stock and open documents.
- Training and pilot: running alongside the old system, checking month-end close and reports.
- Go-live and review: after a few months, measure order processing time, stock errors and close time, and calculate the ROI.
Common mistakes
- Choosing an ERP based on the vendor's demo, not your own processes.
- Migrating the chaos: old, uncleaned code lists and duplicate products.
- Too much customisation, which makes every upgrade more expensive.
- An ERP not connected to the online store and website, so orders are still retyped.
- No internal project owner who makes decisions and keeps deadlines.
When to bring in a specialist
Selecting and implementing ERP takes months, so it pays to have someone besides the software vendor who represents your processes. At Weboptim we help with process analysis, connecting ERP to the online store, website and other tools, and automating what the ERP cannot do on its own as part of our digitalisation and automation service. If your focus is sales integration, see also e-commerce development with stock and accounting connections.
Frequently asked questions
What is ERP in simple terms?
ERP is business software that combines accounting, stock, purchasing, sales, production and payroll in one database. Data is entered once and every department uses it without retyping.
What does ERP stand for?
ERP stands for Enterprise Resource Planning. The term has been used since the early 1990s and builds on the MRP and MRP II manufacturing systems.
What is the difference between ERP and CRM?
CRM manages customer relationships and sales before the order; ERP manages what happens after it: stock, production, invoicing and accounting. Ideally they are connected so a won deal flows into the ERP automatically.
Does a small business need an ERP system?
Not always. A small business without stock usually only needs invoicing or accounting software plus automation. ERP pays off once you hold stock, sell through several channels or manufacture, and retype data between systems.
Is cloud ERP or on-premise ERP better?
For most small and mid-sized companies cloud ERP is more practical: lower upfront cost and the vendor handles updates. On-premise makes sense with specific security, performance or deep customisation requirements.