Specification of hard real-time industrial automation systems with UML-PA

Nowadays Unified Modeling Language (UML) has found widespread use in software development of commercial IT systems. But the application in industrial automation is still rare. The domain of process automation involves special requirements on software development. Important requirements on the notation used for software specification arise from the real-time characteristics of industrial automation systems. In order to consider these requirements in software design to avoid a hard clash in development between design and implementation the UML notation has to be used in a specific manner. UML for process automation (UML-PA) simplifies system and software development for distributed real-time systems. This paper presents adoptions of UML regarding real-time specific modeling elements.