Modeling And Analysis Of Embedded Real-time Software Based On UML And Time ER Nets

With the rapid development of computer technology, embedded real-time software has been widely used in a variety of domains, and plays a more and more important role in our daily life. Compared with other software systems, the embedded real-time software has stricter timing constrains, and calls for much more reliability and safety. Therefore, it is beneficial to specify and analyze timing constraints of embedded real-time software at an early phase to efficiently guarantee the timely execution of expected functions. However, due to the widespread use of more powerful hardware in embedded systems, the size and complexity of embedded read-time software are increasing rapidly, which brings new difficulties to the development of the embedded real-time software. Component technology whose key factors are reusability and extensibility enables software systems to be built by assembling components that have already been developed before, so it is an effective technology to raise software productivity, improve software quality, and shorten development cycle. Therefore, we propose an approach to modeling and analyzing embedded real-time software with the guidance of component technology.In this paper, we first give an overview of UML and formal methods, and introduce the relevant concepts of Time ER nets. Since UML is limited by the lack of constructs to express time-related constraints, we adopt the UML extension mechanism to augment UML diagrams with timing information. And then, the scenario-based requirement models and behavior models of the embedded software are specified with the time-extended UML diagrams. Because of the lack of precise semantics, it is difficult for UML to analyze the models it describes. Therefore, in order to enable timing analysis based on UML diagrams, we propose some mapping rules to transform UML diagrams into Component Time ER nets (CTERs), which extend Time ER nets to support compositional timing analysis. After that, conflicts among timing requirements are incrementally checked by compositional analysis on the Component Time ER nets. Finally, we take the Guard System of a Golf Course as an example to elaborate the application of the proposed approach.It is beneficial for embedded real-time software to analyze timing constraints as early as possible to build dependable software systems. The approach proposed in this paper exploit the advantage expected from component-based approach, UML and Petri Net-based formalism to efficiently specify and analyze timing constraints of embedded real-time software in a compositional way. And with the approach, we can not only check the conflicts of given timing constraints in software systems but also achieve the expected benefits from both technologies such as reusability and extensibility of components.