Task model — system model: towards an unifying formalism

Abstract

This chapter proposes a way for translating from a user action notation (UAN) description to a Petri net one. For every UAN construct, a Petri nets is proposed, which interpretation is the same as the one of the UAN description. As one uses Petri nets for modeling the interactive application, cooperation between the model of the tasks and the model of the system can be mathematically checked, in order to ensure before implementation that the system performs all the user's requests included in the task models. In addition, as the model of the system is embedded at run time, it can be used to provide contextual help about the behavior of the system. When the task model is also embedded within the same formalism, the help may be given not only with respect to the system behavior but also with respect to the user's task and goal.