The application migration diagram identifies application migration from baseline to target application components. It enables a more accurate estimation of migration costs by showing precisely which applications and interfaces need to be mapped between migration stages.

The aim is to define the trajectory between the current version of the IS and the version that you wish to obtain, over several stages. The component deployment technique enables you to present the same component deployed in several versions of the IS, and interconnected differently according to the context.

Migration strategy in three steps

In this diagram, we see that the "Travel" application component will be developed in three versions. The first one will still be based on the TravelPortfolioManagement (legacy) application, whilst the second version will work on its own, with direct access to the repository.

Each version of the IS is represented by a different "system element" in which occurrences of application components are deployed. This allows you to show that the same application component is used in several versions, or that an application component in version N will migrate into one or several application components in version N+1.