While Microsoft has bundled a number of products under the umbrella of "Dynamics 365", they really are separate products with separate histories serving different needs; understanding how the CRM product functions isn't going to give you much of an idea of how their various ERP products work. Where these products share (or will eventually share) common elements is at the data and integration levels – the Common Data Model and Common Data Service ( Power Apps, Flow, and Power BI). To support an ERP well, you really need a background in the following core areas:
Depending on the type of business you are supporting, you may also need a knowledge of Production Management, Warehouse Management and yes, CRM.
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