How long does an ERP implementation take? Realistic timelines by business size

"How long will it take?" is a fair question, and the honest answer depends on the size and shape of your business more than on the software. Here are realistic timelines based on the projects we run, and the things that make them longer or shorter.

Typical timelines by business size

Small business, simple scope: 4 to 6 weeks. Up to around 10 users, two or three modules (for example CRM, sales and invoicing), no stock or simple stock, clean data, standard features. Common for services businesses.

Small business, standard scope: 6 to 10 weeks. 10 to 30 users, three to five modules including stock and purchasing, migration of customers, products and opening balances, some custom fields and reports, department-by-department training. This is where most of our clients sit.

Mid-sized or complex: 12 to 20 weeks. 30 to 100 users, multiple warehouses or companies, manufacturing, integrations with other systems, custom modules, several years of data.

Large or multi-site: 20 weeks or more. Multiple countries, complex consolidation, phased rollouts by site.

These assume a partner-led project with a clear specification. See ERP implementation step by step for what happens in each phase.

What makes a project longer

• Dirty data. Cleaning years of duplicated customers and inconsistent product codes is the single most common cause of delay. Start early. Our data migration guide explains what to do.
• Slow decisions. Every "we will get back to you" adds days. Give the project a lead on your side who can decide.
• People not available. Discovery workshops, testing and training need your department leads. If they cannot get time, the project waits.
• Changing requirements. Some refinement is normal. Reopening decisions every week is not.
• Integrations. Each external system adds design, build and testing time, and depends on the other system's API being ready.
• Custom development. Standard features are configured in hours. Custom modules take weeks.

What makes it shorter

• A written brief before the project starts. See how to write a software brief.
• Using standard features where possible.
• Phasing: core modules first, everything else later.
• Clean data ready before migration.
• A go-live date chosen at a period boundary and protected.

Why phasing works

Trying to go live with every module at once stretches the timeline and the team. A better pattern is:

1. Phase one: the modules that fix the biggest pain, usually sales, stock, purchasing and accounts. Live in 6 to 10 weeks.
2. Phase two: CRM, projects, HR, eCommerce or manufacturing, added once the team is comfortable.

Each phase is shorter, less risky, and informed by what you learned in the last one.

A realistic example

A wholesale business with 20 staff, one warehouse, around 2,000 products and Xero for accounts. Scope: sales, stock, purchasing and accounting in Odoo, migration from Xero and spreadsheets, a Shopify integration in phase two.

Week 1 to 2 discovery and specification. Week 3 to 4 configuration and first migration test. Week 5 to 7 build of custom reports and price lists, user testing. Week 8 training. Go-live at the start of the VAT quarter in week 9, with two weeks of hypercare. Shopify integration follows in weeks 12 to 15.

Getting a date for your project

We can only give a real timeline after a discovery call, because we need to understand your modules, data and integrations. That call is free and takes 30 minutes. Read about our ERP service or request a quote.

Frequently asked questions