PETRI NET MODULES

摘要

Here we present a new module concept for Petri nets that is based on the component conceptsrnof Continuous Software Engineering (CSE). According to that concept two distinguished interfaces arernrequired. These are import and export interfaces. The import describes the assumptions on the environment,rne.g. in terms of used components. The export gives an abstraction of the functionality and presents e.g. thernoffered services.rnThe modules for Petri we introduce here consist of three nets for the import, the body of the module and thernexport. The import net IMP states the prerequisites the modules assumes. The body net BOD representsrnthe internal functionality. The export net EXP gives an abstraction of the body that can be used by thernenvironment. We provide module operations to compose larger modules from basic ones. Operations torncompose Petri net modules are crucial as the main purpose is composition. In most approaches modulernconcepts come along with just one operation. A great advantage is achieved having different possibilitiesrnto compose modules, as it increases the convenience of modeling large systems. We propose three differentrnoperations, composition, disjoint union, and union. Our main result in this contribution is that these modulernoperations are compatible with each other.