Phase 1 · Awareness Enterprise architecture and ecosystem integration

Legacy ERP migration: Dynamics AX, SAP and Dynamics GP to cloud-native Dynamics 365

A framework for moving from Dynamics AX, SAP, Dynamics GP or a bespoke system to Dynamics 365, with the cutover rehearsed until the downtime is a known, short window.

← All thought leadership

Migration framework For CIOs, CFOs, programme directors

The short answer

The route depends on where you start. Only Dynamics AX 2012 has an upgrade path into Finance and Operations. Everything else is a migration: design the new processes, then move masters and the open position, reconciled.

Stages

Five stages from legacy to live

1
Assess Inventory processes, customisations, integrations and data. Decide what is kept, retired or rebuilt.
2
Design Design on standard Dynamics 365 first. Write the map of what moves, what is transformed and what stays behind.
3
Load and reconcile Run trial loads and reconcile to the source before every rehearsal.
4
Rehearse the cutover Run at least two full dress rehearsals and time every step.
5
Cut over and stabilise Freeze the source, load the delta, reconcile on the morning, and support the first close.

Decision points

Three questions that change the answer

Are you on Dynamics AX 2012?

YesA brownfield upgrade to Finance and Operations is available. Decide what customisation to keep.

NoThis is a migration. Design first, then move masters and open items.

Do you need the full history in the new system?

YesPlan a history load and reconcile it, accepting the cost and the clean-up.

NoKeep history readable in the old system and load opening balances only.

Can the business stop for a weekend?

YesPlan a single cutover window.

NoPlan a phased cutover by entity, with an intercompany bridge.

Milestones

What done looks like, and when

Month 0 to 2 Assessment complete, route chosen, data owners named.
Month 3 to 6 Design signed off, first trial load reconciled.
Month 7 to 9 Two dress rehearsals complete with timings.
Go-live Cutover window, reconciliation sign-off, hypercare begins.

Principles we hold to

Do not migrate a record you would not enter by hand.
Every opening balance ties back to the source.
Integrations are rebuilt against Dynamics 365, never pointed at the old database.
Rehearse until the window is boring.

Frequently asked questions

Can we upgrade SAP or Dynamics GP to Finance and Operations?

No. They are migrations: the design is rebuilt on Dynamics 365 and data is moved and reconciled.

How long does a migration cutover take?

It depends on volumes and the number of entities. The rehearsals produce the real number, which is why we run them before agreeing the window.

Related Dynamics 365 ERP project types → The core system stays, the books become Dynamics 365 → Implementation services →

Take this to your own programme. Tell us where you are. We will tell you plainly what this means for your estate and what we would do first. Book a consultation Next: Multi-country and multi-entity rollout: a playbook for cross-border Dynamics 365 →

How an engagement runs

It starts with a 45-minute consultation, then a discovery and fit-gap workshop on your own processes. You receive a written fit-gap and a phased plan before a programme is agreed. Four phases follow, each with something you can use and review.

Discover

Process workshops, data audit, and a fit-gap against the standard product.

Design

Solution blueprint, integration map, and the extensions we will actually need.

Deploy

Configuration, migration rehearsal, role-based training, UAT and phased cutover.

Support

Hypercare, managed services, client portal, scheduled optimisation reviews.

What drives the cost: users, legal entities and currencies, integrations, data migration and the gaps found against standard. See how pricing works, run the three-minute readiness score, or book a consultation.