Outeroperability

One of the differences between IHE and HL7 is in how the two organizations approach the dynamic interaction model.  IHE has actors which exchange information in transactions.   HL7 (version 2 and 3) have application roles and interactions which exchange information using messages.  But the traditional focus is a bit different in the two organizations.  In V3, very little attention is given to story board and application roles.  Most of the attention goes to the information models, the various *IM diagrams that are generated.  In IHE, about 50% of the technical detail in a profile is related to the information model -- constraints on data.  The other 50% (sometimes even more), is on required behaviours.  It isn't enough to just recieve the message, the reciever has to do something (operate with) the information it recieved from elsewhere.

This material is covered in the HL7 specifications, it just doesn't have as much an impact on how the specification is written.  And within different domains, these generalizations don't always apply.  For example, most of PCC's early work was about data constraints (templates).  And some HL7 domains focus very much on dynamic behaviours.

This is the real key to interoperability is to be able to operate with information recieved from outside your system.  I think it should really be called outeroperability.