A multi-tenant shop-floor platform where the first question is which products the customer actually licenses.
The defining translation
Plex is a portfolio of separately licensed SaaS products sharing one multi-tenant platform, and it models many sites and plants inside a single tenant with roll-up reporting rather than as hard legal entities. Deciding whether a Plex site becomes a D365 legal entity or a site and warehouse beneath one is the highest-impact and least reversible decision in the engagement. Inventory, lot and serial genealogy sit under Plex MES rather than Plex ERP, account determination is not publicly documented, and there is no version to freeze.
Signature change
Site / plant topology in one tenant → Legal entities + sites + warehouses