Une approche formelle pour i'evaluation de la tolérance aux interruptions des système interactifs

This paper presents an approach for investigating potential disruptive effects of interruptions on task performance in a multitasking environment. The approach combines previous work in the field of interruption analysis, formal description techniques for interactive systems and stochastic processes to support performance analysis of user tasks constrained by the occurrence of interruptions in the working environment. The approach uses formal description techniques to provide a comprehensive description of user tasks, system and interruption behaviour. The detailed mechanism by which systems and interruptions behave is presented using a Petri nets-based formal description technique called Interactive Cooperative Objects (ICO). The use of a formal modeling technique for the description of these three components makes it possible to compare, analyze and integrate them. In particular, it allows us to determine which of the system states are actually affected by the occurrence of interruptions. The approach is exemplified by a case study that implements two interaction techniques for manipulating icons in a desktop environment.