 An MDM system can act as the source of truth for any given entity that might not necessarily have an alternative "source of truth" in another system.Typically the MDM acts as a hub for multiple systems, many of which could allow (be the source of truth for) updates to different aspects of information on a given entity.For example, the CRM system may be the "source of truth" for most aspects of the customer, and is updated by a call centre operator.