Modernise the platform without carrying every legacy decision.

An upgrade is not a licence to carry forward technical debt. The first decision in any NAV or legacy Business Central migration is not technical, it is editorial: which of the decisions embedded in the current system still describe how the business works, and which are historical accidents that only survive because nobody has been given permission to retire them. Greenfield or brownfield There are two honest routes to the modern platform. A technical upgrade carries the existing objects, data and structure forward and remediates them — right when the estate is fundamentally sound and the customisations are understood. A reimplementation configures the standard product fresh and migrates data into it — right when the customisation load is heavy, poorly understood, or describes a business that no longer exists. The choice is made with an inventory in hand, not by preference: version, object, extension and dependency facts first, then the route. What the programme covers Version, object, extension and dependency inventory: what actually exists, what depends on what, and what has quietly stopped being used. Keep, replace, retire or redesign decisions: every customisation gets a disposition, and retirement is more common than expected — requirements written years ago are often covered by the standard product now. Data upgrade and environment strategy: which history migrates, which is archived, and how sandboxes, test cycles and the production cutover are sequenced. Report, integration and automation remediation: the surrounding estate — reports, integrations, automations — converted or replaced against the modern extension model, never patched into place. Regression evidence and controlled production cutover: critical business scenarios proven on the target platform before anyone commits, then a cutover with reconciliation evidence rather than optimism. Why waiting costs more Business Central ships two major updates a year and applies minor updates continuously. Every release the legacy estate skips widens the remediation gap and raises the regression risk of the eventual move. The estate does not stay still while you wait — it falls further behind a platform that is moving. What you leave with Explicit legacy-dependency and customisation decisions, converted extensions aligned to a governed pattern, regression coverage for the scenarios the business actually depends on, and the release, environment and update operating rules that keep the new estate on the supported path.