Many model-based approaches for user interface design start from a task model, for which the ConcurTaskTrees notation is frequently used. Despite this popularity and the importance that has been given to a close relation with UML, no relation has been established with UML state machines, which have been shown to be useful for the description of the behavior of user interfaces.
This paper proposes a general description of the task execution cycle using UML state machines. We described the influence of the temporal operators on this description. An example that combined the states for a complete task model into one stage machine demonstrated the complexity of the notation for larger compositions. We thus proposed an abbreviated notation for this integrated notation using a small UML profile. This profile adds extra semantics to the states, which can be used to generate the complete specification. The support for nested states offers enhanced expressiveness over other solutions such as state transition networks.
The usage of UML enables the application of proven transformation tools to be applied on the models to generate dialog models at different levels of abstractions and adapted to different contexts of use. Further exploration of this route is planned as future work.
Read this article on http://research.edm.uhasselt.be/jvandenbergh/cttStatecharts.pdf