An ERP implementation checklist, phase by phase

The short answer

An ERP implementation checklist should cover six phases: scope and team, process design, data migration, integrations, testing, and go-live with a post-implementation review. The items that most often sink projects are vague scope, dirty data, untested integrations and a cutover plan written the week before launch.

Use the checklist below as a working document. Assign an owner and a date to every line. It assumes you have already chosen your ERP and an implementation partner, and it is written for businesses with roughly 20 to 200 people, where the project team also runs the business day to day.

Phase 1: scope, team and governance

• Write a one-page scope: which modules, entities, locations and processes are in phase one, and what is explicitly out.
• Name an executive sponsor who can settle disputes and approve changes.
• Name a full-time or near-full-time internal project lead. Backfill part of their day job.
• Name process owners for finance, sales, purchasing, inventory and production.
• Agree on how scope changes are requested, priced and approved.
• Set a weekly status meeting with the partner and a simple risk and issue log.
• Define success measures, such as days to close the month, inventory accuracy and on-time shipments.
• Fix a target go-live date that avoids your busiest season and ideally lands at the start of a fiscal period.

Phase 2: process design

• Document each end-to-end process: order to cash, procure to pay, plan to produce, record to report.
• For each step, decide whether to adopt the ERP’s standard way or customize. Default to standard.
• Record every customization with its business reason and who approved it.
• Design the chart of accounts, dimensions and reporting structure before any data is loaded.
• Define roles and permissions, including approval limits and segregation of duties.
• Agree on document templates: quotes, invoices, purchase orders, packing slips.
• List the reports and dashboards each role needs at go-live.

Phase 3: data migration

Data migration is usually the longest and most underestimated workstream. Start it early.

• Inventory every data source: old ERP or accounting system, spreadsheets, CRM, shop-floor files.
• Decide what moves: master data (customers, vendors, items, BOMs), open transactions (orders, invoices, purchase orders) and opening balances. Keep detailed history in the old system, read-only.
• Assign a business owner to each data object who signs off on its quality.
• Clean before you load: remove duplicates, retire inactive items, fix units of measure and addresses.
• Build repeatable load templates so each trial load is the same process.
• Run at least two trial migrations and reconcile record counts and balances each time.
• Plan the final load: what freezes when, who loads what, and who signs off.

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Phase 4: integrations

• List every system that will connect to the ERP: e-commerce, CRM, payroll, banking, shipping, EDI, tax, BI.
• For each, document direction, frequency, data fields and which system owns each field.
• Choose the method: native connector, integration platform or custom API work.
• Define error handling: where failed records go, who is alerted, how records are resent.
• Use dedicated integration accounts with least-privilege access, not personal logins.
• Test each integration with realistic volume, including your peak day.
• Plan a reconciliation report for each critical flow, such as daily store orders versus ERP orders.

For a worked example of these decisions, see our guide to QuickBooks, Shopify and CRM integration.

Phase 5: testing

Microsoft’s Dynamics 365 implementation guide describes the test types most projects use: unit, functional, process, end-to-end, user acceptance, regression and performance testing. It also recommends always planning a mock cutover, a timed rehearsal of the go-live steps. That applies to any ERP.

1. Unit tests: each configuration and customization works on its own.
2. Process tests: each end-to-end process runs from start to finish in the system.
3. Integration tests: data flows correctly between the ERP and every connected system.
4. Data validation: migrated balances, open orders and inventory match the old system.
5. User acceptance testing: the people who will do the work run real scenarios with real data and sign off.
6. Performance: the system copes with month-end and peak order volume.
7. Mock cutover: rehearse the go-live steps, timed, end to end.

Track every defect with an owner and severity. Agree in advance which severities block go-live.

Why ERP projects slip, and how to prevent it

• The project lead still has a full day job. Free up real time, or every decision waits a week.
• Decisions get reopened. Record each design decision with a date and owner, and only reopen it through the change process.
• Customizations pile up. Each one adds build time, test time and upgrade risk. Ask whether a process change would do instead.
• Data cleanup starts late. Begin in the first month, not after configuration is done.
• Testers are too busy. Book UAT time on calendars weeks ahead, and give testers scripts based on their real work.
• Integrations are left to the end. Build and test the most important connection early, so problems surface while there is still time to fix them.
• Go-live lands in a busy season. Move the date rather than launch into your peak month.

Phase 6: go-live checklist

• Sign-off from each process owner that UAT passed.
• Final data load completed and reconciled.
• All integrations switched to production and tested with one live transaction each.
• Users created, roles assigned, old system access set to read-only.
• Role-based training completed, with quick reference guides published.
• Printers, label printers, scanners and forms tested in production.
• Support plan for the first two weeks: partner on call, internal floor walkers, a single place to report issues.
• Rollback plan documented: what triggers it and how to execute it.
• Backups of the old system taken and verified.
• Customers and vendors told about any changes to invoices, portals or remittance details.

After go-live: the post-implementation review

Schedule a review 60 to 90 days after launch. Cover:

• Success measures versus the baseline you set in phase one.
• Open defects and workarounds still in use.
• Integration error rates and manual fixes per week.
• Training gaps, especially for new hires.
• Budget versus actual, including internal time.
• The phase-two list: features and modules deferred from phase one.

Microsoft’s guidance also stresses that training is ongoing and does not stop when the system goes live. Build a short refresher into your review.

JLB USA handles systems integration for ERP, CRM, accounting and web apps, and automation to remove manual steps around them.

Keep reading

• QuickBooks Online vs Desktop in 2026: which should a growing business use?
• HubSpot QuickBooks integration: what it syncs, how to set it up and where it falls short
• CRM implementation checklist: goals, data, integrations, training and adoption
• QuickBooks integration with Shopify (and your CRM): how to set it up right

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