What should you do first when planning a Dynamics AX migration?

When planning a Dynamics AX migration, the first thing you should do is run a migration readiness assessment before committing to a roadmap or budget. This means taking a clear-eyed look at your current data quality, business processes, integrations, and internal capacity. Without that baseline, you risk building a migration plan on assumptions rather than facts. Below, we answer the most common questions that come up at the start of a Dynamics AX migration project.

What does a Dynamics AX migration actually involve?

A Dynamics AX migration is the process of moving your organisation off Microsoft Dynamics AX (now out of mainstream support) and onto a new ERP platform, most commonly Microsoft Dynamics 365. It involves migrating your data, reconfiguring or rebuilding business processes, integrating third-party systems, training users, and managing the technical cutover from the old environment to the new one.

Unlike a simple software upgrade, a Dynamics AX migration often touches every part of the business. Finance, supply chain, warehouse management, procurement, and HR processes all need to be reviewed, mapped, and either replicated or redesigned in the new system. This is not just an IT project. It is a business transformation that requires coordination across departments and careful planning from day one.

The migration also involves decisions about what to carry forward and what to leave behind. Custom code built on top of AX, legacy integrations, and years of accumulated data all need to be evaluated. Some of it will be migrated as-is. Some will be rearchitected. Some will simply be retired. Making those calls early saves significant time and cost later in the project.

Should you migrate to Dynamics 365 or switch to a different ERP?

For most Dynamics AX users, migrating to Microsoft Dynamics 365 Finance and Operations is the most practical path. It shares conceptual DNA with AX, which reduces the learning curve for your team and often simplifies data migration. That said, a Dynamics AX migration is also a natural moment to evaluate whether Dynamics 365 is still the right fit for your organisation’s size, industry, and future direction.

If your business has grown significantly since the original AX implementation, or if your industry has specific requirements that another platform handles better, this is the time to explore alternatives. SAP S/4HANA, for instance, is a common alternative for large multinationals with complex supply chains. The evaluation should be based on your current business requirements, not on the fact that you already run AX.

That said, switching platforms entirely adds cost and complexity. A like-for-like migration to Dynamics 365 is generally faster and lower risk than a full platform switch. If you are leaning toward a change, factor in the additional time for data model differences, user retraining, and integration rework. We cover both paths across our full range of services, including SAP and Microsoft Dynamics environments.

What is a migration readiness assessment and why run one first?

A migration readiness assessment is a structured evaluation of your organisation’s current state across three dimensions: your data, your processes, and your people. It tells you where you stand before you commit to a timeline, a budget, or a specific migration approach. Running one first is one of the most useful things you can do at the start of a Dynamics AX migration.

Without a readiness assessment, you are essentially estimating the scope of the project without knowing what is actually inside the system. Data quality issues, undocumented customisations, and process gaps tend to surface mid-project when they are expensive to fix. An assessment surfaces them early, when you can still make design decisions around them.

A good readiness assessment covers:

Data quality and volume: What data exists, how clean it is, and what needs to be cleansed or restructured before migration
Process mapping: Which current processes are well-documented and which need to be captured before the new system is configured
Custom code inventory: What has been built on top of AX and whether it needs to be rebuilt, replaced, or retired
Integration landscape: Which third-party systems connect to AX and how those connections will need to change
Internal capacity: Whether your team has the bandwidth and expertise to run or support the migration

This is exactly where we typically start with clients. Our data migration management approach begins with a thorough As-Is analysis so that the migration plan reflects reality, not assumptions.

What are the biggest risks in a Dynamics AX migration?

The biggest risks in a Dynamics AX migration are poor data quality, underestimated scope, and a rushed cutover. These three factors account for the majority of go-live failures and post-launch disruptions. Understanding them upfront helps you build a plan that accounts for them rather than discovering them under pressure.

Data quality is consistently underestimated. AX systems that have been running for years often contain duplicate records, inconsistent formats, and data that was entered manually without validation rules. Migrating that data as-is into a new system does not clean it up. It just moves the problem. Rigorous data cleansing and testing before migration is not optional.

Scope creep is another major risk, particularly when business stakeholders use the migration as an opportunity to redesign processes. That is not necessarily wrong, but every process change adds time and complexity. Scope needs to be tightly governed from the start, with a clear change control process.

Cutover risk is the highest-stakes phase of any migration. The window between switching off the old system and going live on the new one leaves no room for surprises. Cutover needs detailed planning, dry runs, and real-time monitoring. It also needs a clear rollback plan in case something goes wrong. Post-go-live hypercare is equally important. The first weeks after launch are when issues surface and user confidence is formed.

How long does a Dynamics AX migration typically take?

A Dynamics AX migration to Dynamics 365 typically takes between 12 and 24 months for a mid-to-large organisation, depending on the complexity of your current environment, the scope of process changes, and the number of legal entities or geographies involved. Smaller, more contained implementations can be delivered faster. Highly customised AX environments with many integrations take longer.

The phases that most often take longer than planned are data migration, user acceptance testing, and change management. Data migration in particular tends to require multiple iterations before the data is clean and complete enough to go live. Building in buffer time for these phases is not pessimism. It is realistic planning.

A rough timeline for a standard migration looks like this:

Months 1 to 3: Readiness assessment, project setup, and solution design
Months 4 to 9: System configuration, data cleansing, and integration development
Months 10 to 15: Testing cycles, user training, and cutover preparation
Months 16 to 18+: Go-live, hypercare, and post-launch stabilisation

These timelines assume a well-resourced project with clear decision-making. Projects that lack internal sponsorship, experienced programme management, or dedicated business resources consistently run over time and budget.

How Optinus helps with Dynamics AX migration planning

We work with organisations at every stage of a Dynamics AX migration, from the first readiness assessment through to post-go-live hypercare. Our consultants have hands-on experience from real ERP migrations at leading multinationals, not just methodologies on paper. We are active across both Microsoft Dynamics 365 and SAP environments, and we cover the full spectrum from project manager to business architect.

Here is what working with us looks like in practice:

We start with a maturity assessment to give you a clear baseline before any budget or roadmap is committed
We manage data migration using rigorous As-Is/To-Be analysis and testing procedures specifically designed to prevent data loss and errors
We handle cutover management end-to-end, including dry runs, real-time monitoring, and post-go-live hypercare
We address the people side of the migration through change management that drives genuine adoption, not just checkbox training
We are available both on-site and remote, across the Netherlands, Belgium, and internationally

Ready to start your Dynamics AX migration on the right foot? Get in touch with our team to discuss your situation, or learn more about what we do and how we approach complex ERP transformations.

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