ERP projects have a reputation for running late and over budget. The reasons are rarely mysterious. In Dynamics 365 Finance & Operations projects, the same handful of risks appear again and again — and most of them can be reduced by people who have seen them before and know the platform well enough to act early.
Risk 1: decisions made too late
Legal entity structure, financial dimensions, inventory dimensions, number sequences and the integration landscape all shape everything that follows. When they are decided during configuration — or changed during testing — the cost multiplies.
What reduces it: a short, explicit architecture phase that records the key decisions, the options considered and why one was chosen. Not a large document; a set of decisions that the whole project can refer to.
Risk 2: customisation by default
Every requirement can be met with code. That does not mean it should be. Custom code in D365 F&O has to survive every Microsoft service update, and each extension adds testing effort for the rest of the system’s life.
What reduces it: a fit-gap process run by people who know the standard functionality deeply, combined with a clear extension strategy for the gaps that remain. Experienced consultants often find that a requirement is already covered by configuration or a feature that was released recently.
Risk 3: data migration left until the end
Migration is frequently treated as a technical task for the final weeks. In reality it is where data quality problems, missing master data and unclear ownership become visible — usually under time pressure.
What reduces it: starting migration design alongside configuration, running repeated trial loads, and reconciling migrated balances with finance well before go-live. From the second test cycle onwards, test with migrated data rather than demo data.
Risk 4: integrations designed for the happy path
Interfaces that work in a demonstration fail in production when volumes rise, messages arrive twice or an external system is unavailable.
What reduces it: an interface inventory that defines direction, volume, timing, ownership and failure behaviour for every flow, and testing that includes malformed messages, duplicates and outages.
Risk 5: testing screens instead of processes
Testing each form in isolation misses the problems that matter: a posting profile that only fails for one item group, a report that does not reconcile, a workflow that stops when an approver is absent.
What reduces it: end-to-end scenarios — order to cash, procure to pay, record to report — that cross modules and use realistic data, with defects tracked against the process they affect.
Risk 6: an unrehearsed cutover
The go-live weekend is a sequence of technical and business steps with dependencies and timings. When it has never been run in full, the first attempt is the real one.
What reduces it: a cutover runbook with owners and durations, at least one full rehearsal in a production-like environment, and go/no-go criteria agreed in advance.
Risk 7: users who were not prepared
A technically sound system can still fail if the people using it were trained on generic scenarios weeks before go-live and have nowhere to turn when they get stuck.
What reduces it: role-based training on the configured system close to go-live, key users who can answer first-line questions, and visible support in the first weeks.
Why specialisation matters
None of these practices are secret. What makes the difference is recognising the early signs — a dimension design that will not scale, an integration that will need retries, a customisation that duplicates standard logic — while there is still time to change course. That comes from experience on the platform itself.
A focused D365 F&O partner adds the most value at the points where decisions are expensive to reverse: architecture, extension strategy, data and integrations. Bringing that expertise in early is almost always cheaper than recovering a project later.