Brett Peterson very helpfully created the first vision of the Abstract Model. The goal of the abstract model is to formalize the sets of transactions and service orchestrations that are implied in the user stories for the NHIN Direct project. Working off of an abstract model helps us use consistent terminology and ensures that when we look at concrete implementations we don't miss any steps. The use of an abstract model also helps ensure that if we have multiple technology approaches (for example, SMPT-based, REST-based and IHE/SOAP-based), they will all be interoperable because they do consistent operations in consistent ways.
We are close to finalizing the abstract model based on some good discussion and feedback. Please review it an let us know what you think. Please post any comments to the discussion page.