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Dynamics AX 2012 R3 → D365 F&O

The AX → D365 upgrade — de-risked, sequenced, done by people who've done it.

For organisations who know the move off AX 2012 R3 is coming — and keep deferring it. We run the whole journey to Dynamics 365 Finance & Operations: assessment in Lifecycle Services, over-layering re-platformed to extensions, data migrated cleanly, automated testing and a rehearsed cutover into hypercare.

Plan your upgrade See the approach
Approach at a glance
Assessment in LCS✓
Over-layering → extensions✓
Data migration (DMF)✓
Automated testing & cutover✓
Why this matters

The AX → D365 jump is where most teams stall — and it doesn't have to.

AX 2012 R3 is over-layered; D365 is extension-based and continuously updated. That gap is real, but it's well-trodden. The risk isn't the technology — it's a vague plan, untested data and a cutover nobody rehearsed. We remove all three. Here's exactly how we de-risk the move.

The upgrade, end to end

Assess, re-platform, migrate, cut over — step by step.

Assess

Know before you move

A clear, quantified picture of effort and risk before a single line is touched.

LCS
Lifecycle Services assessmentCode, customisation & data estimate via the upgrade tooling.
CODE
Customisation analysisOver-layering inventoried; keep / re-build / retire decisions.
FIT
Fit-gap to standard D365What standard now covers vs. what truly needs extending.
CASE
Business case & planPhasing, effort, risk & a realistic timeline.
Re-platform & migrate

Code & data

The technical heart — customisations modernised and data moved cleanly.

EXT
Over-layering → extensionsCustom code re-built as extensions & chain-of-command.
DMF
Data migration (DMF)Data entities, mapping, cleansing & reconciliation.
INTG
Integrations rebuiltAIF interfaces re-platformed to modern D365 patterns.
DEVOPS
Build automationAzure DevOps pipelines, source control & environments.
Test & cut over

Prove it, then go

Confidence before go-live — and a cutover you control.

RSAT
Automated regression (RSAT)Regression Suite Automation Tool for repeatable testing.
UAT
Structured UATBusiness sign-off scripts & defect management.
MOCK
Mock cutoversRehearsed data loads & cutover dry-runs, timed.
HYPER
Go-live & hypercareControlled cutover, then intensive post-go-live support.
The upgrade map

One programme, four de-risked stages.

Assess, re-platform, migrate and cut over — each gated, each rehearsed, no surprises at go-live.

Assess

LCSFit-gapBusiness case

Re-platform

ExtensionsDevOpsIntegrations

Migrate

DMFCleanseReconcile

Test & cut over

RSATUATHypercare
AX → D365
Upgrade
The differentiators

What de-risks an AX upgrade.

The disciplines that separate a controlled upgrade from a stalled, over-budget one. This is where we prove the practice.

Decide

Keep / re-build / retire — the signature decision

Years of AX over-layering rarely all deserve to move. We inventory every customisation and make a deliberate keep, re-build-as-extension, or retire call — so you carry forward value, not technical debt, and standard D365 does the heavy lifting.

Extensions

Clean-core, extension-based re-build

Surviving customisations re-built as extensions and chain-of-command — never over-layering — so you stay clean-core and One Version updates never break you again.

Data

Data migration that reconciles

Data Management Framework entities, mapping and cleansing, with reconciliation to the penny — balances, open items and master data proven before cutover, not hoped for.

Test

Automated regression with RSAT

The Regression Suite Automation Tool builds a repeatable test pack — so every build is verified fast and One Version updates stay safe after go-live.

Cutover

Rehearsed, timed mock cutovers

Multiple mock cutovers with timed data loads and a detailed runbook — so the real go-live is an execution of a known plan, not a leap of faith.

The challenges we solve

If this is your programme, you're who this page is for.

  • "The upgrade keeps slipping."A quantified assessment and phased plan turns a vague fear into a sequenced programme.
  • "We have years of customisations."A deliberate keep/re-build/retire decision, then a clean extension-based re-build.
  • "We're terrified of the data migration."DMF-based migration with reconciliation and repeated mock loads before cutover.
  • "A previous attempt stalled."We re-baseline, fix the plan and governance, and drive to a controlled go-live.
AX 2012 R3 to Dynamics 365 upgrade
AX → D365
Our specialty

Still on AX 2012 R3? This is the journey we run best.

The AX-to-D365 upgrade is our signature engagement. We've lived through the cutover, and we bring that experience to your programme — so the date you commit to is the date you hit.

Book an upgrade assessment
01
Assess & business caseCode, customisations and data reviewed in LCS; effort and risk quantified.
02
Re-platform & migrateCustomisations re-built as extensions; data migrated and reconciled.
03
Test, cut over & supportRSAT regression, mock cutovers, controlled go-live, then hypercare.
Why Excel Connect Consulting

The team that has lived through the cutover.

Done-it-before seniors

People who have run the AX-to-D365 jump end to end — extensions, DMF, RSAT and cutover — not first-timers learning on your programme.

De-risk obsession

Gated stages, reconciled data and rehearsed cutovers. We'd rather find the problem in a mock run than at go-live.

We stay for hypercare

The same team that built it supports it after go-live — and keeps you safe through One Version updates.

Ready to plan the move off AX 2012 R3?

Start with an assessment — tell us about your estate and a senior upgrade lead replies within one business day.

Book a consultation Back to Dynamics 365