How M3's customisation model — MAK Java modifications, MI program API surface, Smart Office mashups, CMS custom fields, Configuration Packs, and MEC mappings — maps to D365's additive extension model: X++, Chain of Command, form extensions, Power Platform, and Azure DevOps ALM.
M3's extension model is built on a spectrum of modification depth. At the least invasive end, Configuration Packs bundle data and settings without touching code. Moving deeper, CMS tables add custom fields to standard M3 records. Deeper still, Smart Office mashups compose custom screens from MI program data.
Most M3 tenants have accumulated elements at multiple levels. A complete estate inventory must identify all active items at each level because:
D365 F&O is built on a layered application model: the Microsoft standard layer sits at the bottom; ISV solutions add a layer above it; customer extensions add a layer above that. No layer may modify objects in a lower layer directly — it may only extend them.
M3's security model assigns users to roles (via MNS100/MNS150), and roles grant access to program functions (the CONO/function/environment triple). D365's security model uses Role-Based Access Control (RBAC): a role aggregates duties, each duty aggregates privileges, and each privilege defines specific access (Read, Update, Create,…
M3's deployment model for MAK customisations is typically manual: Java class files are compiled and deployed to the M3 application server; configuration changes are applied through M3 programs; the change record lives in a spreadsheet or ticket system.
D365 F&O is closely integrated with the Power Platform: Power Apps, Power Automate, and Dataverse. This provides a low-code extension surface that is appropriate for:
The development backlog should classify every M3 customisation by surface before deciding whether it becomes X++, a data entity change, a Power Platform artefact, or nothing. The useful mapping is:
M3's customisation model runs from Configuration Packs (non-invasive) through CMS fields and Smart Office mashups to MAK Java-source modifications. D365's extension model is structurally different: extensions and Chain of Command add behaviour without touching the base layer; overlayering is prohibited.