This activity only has to be executed in case in activity 1.4 - of the Focus and Direction phase a reference model has been determined. If the scope of the engagement includes the use of a proprietary or public reference model(s) then this is the point where it should be decided which parts of the reference model to absorb or apply during the To-Be Design. A reference model can be considered to be a set of requirements stated in a design format. During this activity it needs to be decided in which streams the reference model will be applied and for each stream which parts of the model will be applied. A reference model may be an accepted industry reference model or a client owned best practice model. This activity is typically performed in close cooperation with the client as it affects the objectives of the engagement. It is typical that the client is involved as much as possible since incorporating (elements of) a reference model can have a major impact on the To-Be Design. It needs to be ensured that the client is aware of this and explicit approval of the client for the requirements/change drivers taken into scope is recommended.

Optionally the parts of the reference model absorbed in the various models may be incorporated in the Business Requirements Catalogue and linked to the various elements to which they apply, similar to the way that Change Drivers are incorporated in the Business Requirements Catalogue.