Original Article

Requirements Engineering

, Volume 9, Issue 2, pp 132-150

First online:

Specifying and analyzing early requirements in Tropos

  • Ariel FuxmanAffiliated withDepartment of Computer Science, University of Toronto
  • , Lin LiuAffiliated withDepartment of Computer Science, University of Toronto
  • , John MylopoulosAffiliated withDepartment of Computer Science, University of Toronto
  • , Marco PistoreAffiliated withDepartment of Information and Communication Technology, University of Trento
  • , Marco RoveriAffiliated withITC-irst Email author 
  • , Paolo TraversoAffiliated withITC-irst

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We present a framework that supports the formal verification of early requirements specifications. The framework is based on Formal Tropos, a specification language that adopts primitive concepts for modeling early requirements (such as actor, goal, and strategic dependency), along with a rich temporal specification language. We show how existing formal analysis techniques, and in particular model checking, can be adapted for the automatic verification of Formal Tropos specifications. These techniques have been implemented in a tool, called the T-Tool, that maps Formal Tropos specifications into a language that can be handled by the NuSMV model checker. Finally, we evaluate our methodology on a course-exam management case study. Our experiments show that formal analysis reveals gaps and inconsistencies in early requirements specifications that are by no means trivial to discover without the help of formal analysis tools.


Early requirements specifications Formal methods Model checking