活动图

活动图（英语：activity diagram）是工作流的图形化表示。^[1]活动图主要由活动和动作构成，也可以支持分支选择、迭代、并行。在 UML 中，活动图主要用于为计算性和组织性过程（即工作流）建模，相关活动之间的数据流也在其覆盖范围之内^[2]^[3]。活动图主要是用来说明控制流，不过也可以显示数据在各数据存储之间的流动^{[来源请求]}。

组成

活动图由若干不同形状的图形组成，图形之间由箭头连接。 ^[4] 其中比较重要的形状有：

圆角矩形：表示“动作”；
菱形：表示“决策”；
粗实线：表示并行（并发性）活动的开始（分离）和结束（汇合）；
黑圆：工作流的开始（初始节点）；
黑圈套住的黑圆：工作流的结束（结束节点）。

箭头从开始一路指向结束，用来表示活动的先后顺序。

活动图可以视为是种结构化的流程图，并且结合了传统的数据流程图。典型的流程图技术中缺乏表示并发性（concurrency）^[5]。不过，活动中的分离和汇合符号只解决了在简单情形下的应用，若是配合决策或是循环，其意义较不清楚^{[来源请求]}。

UML 1.x版的活动图只是一种特殊的状态图^[6]。UML 2.x中的活动图已依照类似佩特里网的语义重新订定格式，增加活动图可以建模的情境^[7]。因此许多UML 1.x的活动图在UML 2.x下会有不同的解读方式^{[来源请求]}。

UML 2.x版的活动图可以用在许多不同的领域中，例如嵌入式系统设计，也可以用模型检查技术验证规格^[8]。

参考资料

^ Glossary of Key Terms. [2017-08-02]. （原始内容存档于2018-06-27）（英语）.
^ UML Revision Task Force. OMG Unified Modeling Language Specification, Version 1.4 (final draft). February 2001.
^ J. Rumbaugh, I. Jacobson, and G. Booch. The Unified Modeling Language Reference Manual. Addison-Wesley, 1999.
^ OMG Unified Modeling Language Superstructure Specification, version 2.1.1. Document formal/2007-02-05, Object Management Group, February 2007. http://www.omg.org/cgi-bin/doc?formal/2007-02-05 （页面存档备份，存于互联网档案馆）.
^ Jibitesh Mishra and Ashok Mohanty. Software Engineering. Pearson Education, 2011.
^ Dumas, Marlon, and Arthur H.M. Ter Hofstede. "UML activity diagrams as a workflow specification language." ≪ UML≫ 2001—The Unified Modeling Language. Modeling Languages, Concepts, and Tools. Springer Berlin Heidelberg, 2001. 76-90.
^ Störrle, Harald, and J. H. Hausmann. "semantics of uml 2.0 activities." Proceedings of the IEEE Symposium on Visual Languages and Human-Centric Computing. 2004.
^ I. Grobelna, M. Grobelny, M. Adamski, "Model Checking of UML Activity Diagrams in Logic Controllers Design", Proceedings of the Ninth International Conference on Dependability and Complex Systems DepCoS-RELCOMEX, Advances in Intelligent Systems and Computing Volume 286, Springer International Publishing Switzerland, pp. 233-242, 2014

[1] Glossary of Key Terms. [2017-08-02]. （原始内容存档于2018-06-27）（英语）.

[2] UML Revision Task Force. OMG Unified Modeling Language Specification, Version 1.4 (final draft). February 2001.

[3] J. Rumbaugh, I. Jacobson, and G. Booch. The Unified Modeling Language Reference Manual. Addison-Wesley, 1999.

[4] OMG Unified Modeling Language Superstructure Specification, version 2.1.1. Document formal/2007-02-05, Object Management Group, February 2007. http://www.omg.org/cgi-bin/doc?formal/2007-02-05 （页面存档备份，存于互联网档案馆）.

[5] Jibitesh Mishra and Ashok Mohanty. Software Engineering. Pearson Education, 2011.

[6] Dumas, Marlon, and Arthur H.M. Ter Hofstede. "UML activity diagrams as a workflow specification language." ≪ UML≫ 2001—The Unified Modeling Language. Modeling Languages, Concepts, and Tools. Springer Berlin Heidelberg, 2001. 76-90.

[7] Störrle, Harald, and J. H. Hausmann. "semantics of uml 2.0 activities." Proceedings of the IEEE Symposium on Visual Languages and Human-Centric Computing. 2004.

[8] I. Grobelna, M. Grobelny, M. Adamski, "Model Checking of UML Activity Diagrams in Logic Controllers Design", Proceedings of the Ninth International Conference on Dependability and Complex Systems DepCoS-RELCOMEX, Advances in Intelligent Systems and Computing Volume 286, Springer International Publishing Switzerland, pp. 233-242, 2014

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组成

相关条目

参考资料