Rigorous Description of Software Requirements with UML

UML supports requirements modeling by means of ``use case'' diagrams. Unfortunately, use cases suffer from several limitations, especially as far as precision and formality are concerned. Rigorous approaches --not based on UML-- were proposed, but they did not achieve a great popularity, mainly because they are considered too difficult to be productive in the short term. Another reason is that since they do not use UML, they are considered not promptly applicable in UML-based development processes. The goal of this paper is to explore the possibility of removing obstacles to the adoption of rigorous approaches by making them applicable in the context of the familiar UML language. The final goal is to increase the quality of requirements models, while making them suitable to drive UML-based software development