Given the understanding of the As-Is Application Model and the business requirements and drivers that initiate change a design exercise is done to create a To-Be Application model. The objective of this exercise is to translate the business requirements and drivers into new or changed applications or parts of this such that business requirements and drivers are met. This may make some existing applications or components obsolete at the same time. Creating a design is not a straightforward mechanical process but requires experience and design creativity. There may be many ways to satisfy business requirements and it is up to the designer to come up with a solution that will yield an effective and efficient solution. At he same time there are constraints to take into account. A proper design not only meets business requirements but also must be feasible in the sense that the design can be transformed into a working solution.

The To-Be Application Model is a picture of the end state solution focused on what needs to change compared to the as-is situation. The design should not only show the desired end state situation but should also indicate what design decisions have been taken to provide the rationale for the design. In other words the designer needs to explain what decisions have been taken to meet business requirements and how these decisions become apparent in design elements.