ERP Modules Explained: What Each One Does
A plain-English guide to ERP modules: finance, sales, CRM, purchasing, inventory, manufacturing, HR, projects, eCommerce and how to decide which ones you need first.
An ERP is a set of modules that share one database. Each module covers one part of the business. Here is what the common ones do.
Finance and accounting
The general ledger, receivables, payables, bank, taxes, assets and financial reports. Every other module posts here. See accounting in ERP.
Sales
Quotes, sales orders, price lists, discounts and invoicing. Sales checks stock and credit limits and sends work to the warehouse.
CRM
Leads, opportunities, pipeline and activities. Some ERPs include CRM; others integrate with one. See ERP vs CRM.
Purchasing
Requests for quotation, purchase orders, vendor prices, approvals and vendor bills. Linked to inventory for replenishment.
Inventory and warehouse
Stock by location, receipts, transfers, picking, packing, shipping, lots and serials, and valuation. See our inventory management guide.
Manufacturing
Bills of materials, routings, work orders, MRP planning, shop-floor control and costing. Add quality, maintenance and PLM for more control.
HR and payroll
Employees, contracts, leave, attendance, expenses, recruitment and payroll. Payroll is very country-specific, so check localisation.
Projects and timesheets
Projects, tasks, timesheets, planning and project billing. Essential for service businesses.
eCommerce and POS
Online store and point of sale connected to stock and accounting. See Odoo eCommerce and Odoo POS.
Helpdesk and field service
Support tickets, SLAs and on-site service visits.
Reporting and BI
Dashboards and reports across modules, plus connectors to BI tools.
Which modules do you need first?
Start with the modules where problems cost the most. A common first phase:
- Distributors: sales, purchasing, inventory, accounting
- Manufacturers: the above plus manufacturing
- Service firms: CRM, projects, timesheets, accounting
Add the rest once phase one is stable.
Modules in Odoo and ERPNext
Odoo calls modules "apps"; see our Odoo modules explained page. ERPNext groups them into modules such as Accounting, Stock and Manufacturing. Both let you start small and grow.
Frequently asked questions
What are the core ERP modules?
Finance and accounting, sales, purchasing and inventory are the core of most ERP systems. Manufacturing, HR, projects and CRM are added depending on the business.
Should we implement all ERP modules at once?
Usually not. Start with the modules that solve the biggest problems, go live, then add more in phases.
Written by
ERP Builders Team · ERP consultants and engineers
Articles written and reviewed by the ERP Builders delivery team — functional consultants, solution architects and developers who implement, integrate and support ERP systems.
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