Reference Information Model | RIM

The Reference Information Model (RIM) is the HL7 version 3 model that is the basis for messaging. The RIM is developed using object-oriented methods developed by computer scientists during the 1980’s.

The HL7 RIM, is based upon the Unified Service Action Model (USAM), which includes three generic classes: services (actions), stakeholders (people), and material (things). On this basis, the RIM constructs its “backbone” classes–entity, role, and act—from which all other classes are derived.

HL7 is migrating to XML and/or JSON encoding (starting with version 3.0 and FHIR) to provide for a more powerful mechanism for encoding messages than the existing ASCII text encoding used for version 2. However, the HL7 strategy is not simply to re-encode HL7V2.x in XMLbut rathertrather to define (with HL7 V3.0) a Reference Information Model (RIM) and message definition within the context of this RIM.