the elements should be accessible via API, and developers should be
familiar with the internal structure of model. Linking executable routines to particular model elements allows
initiating execution of the routines by clicking on the next element in the model that should be executed. This
implementation differs from the traditional information system development approach where the implementation of
specific activities is tied to user interface elements. Users of the systems implemented in the aforementioned way
can initiate execution of processes directly from graphical diagrams, not just using the traditional interface controls
(windows, menus etc.).
The direct execution approach is usable if and only if: (1) the model precisely and definitely describes all
artefacts essential for execution, (2) model is executable (either manually or by computer).