Abstract: As an OO analysis and design modeling language, UML has been used in many large systems. However, the semi-formal property of UML makes it difficult to support the rigorous semantic analysis and accuracy verification of the models. Being an important part of UML dynamic describing mechanism, sequence diagram has the disadvantage described above too. Petri nets is another modeling tool, it has rigorous formal semantics and many mature analysis methods. Based on UML2.0 sequence diagram model, this paper combines several simple structures which have been put forward before, and proposes an algorithm of converting sequence diagram to Petri nets model, finally the effectiveness of this algorithm is demonstrated by an example.

Key words: UML; Sequence diagram; Petri nets

摘要： 作为一种面向对象分析和设计建模语言，统一建模语言(UML)已经越来越多的被用在大型系统中，然而，UML 是半形式化的，这使得很难对其进行严格的语义分析和正确性验证。顺序图作为UML 动态描述机制的重要组成部分，同样存在这样的问题，而Petri 网作为一种建模工具，有着严格的形式化语义，而且有很多成熟的分析方法。该文针对UML2.0 顺序图模型，结合几个简单Petri 网结构，提出了将顺序图转换为Petri 网的算法，最后通过实例说明了转化算法的有效性。

关键词: 统一建模语言；顺序图；Petri 网