Creating the To-Be Transaction Model should be considered an add-on to the To-Be Application Model and the To-Be Interface Model is the dynamical behaviour of the application model is a key design parameter. In complex application landscapes the application model and interface model are not sufficient to explain the support the applications will give to business processes. This is the case where message exchange scenarios are important for business processes. This may involve complex messaging such as in controlling supply chains but can also be where the involvement of a customer environment is a critical business factor.

The To-Be Transaction Model is usually expressed through a UML like sequence diagram. The diagram shows the internal and external applications involved and gives an overview of the messages exchange that is defined by a messaging scenario or business transaction.

To emphasise the changes in the Transaction Model the As-Is Transaction Model is often used as the baseline for the To-Be Transaction Model. This will make it more easy to understand the changes applied to the As-Is Transaction Model rather than the overall To-Be Transaction Model.