Modeling System Requirements Using Use Cases and Petri Nets

The fundamental problem associated with software development is a correct identification, specification and subsequent implementation of the system requirements. To requirement specifications, designers often creates use case diagrams from Unified Modeling Language (UML). These models are then developed by further UML models. To validate requirements, its executable form has to be obtained or the prototype has to be developed. It can conclude in wrong requirement implementations and incorrect validation process. The approach presented in this work focuses on formal requirement modelling combining the classic models for requirements specification (use case diagrams) with models having a formal basis (Petri Nets). Created models can be used in all development stages including requirements specification, verification, and implementation. All design and validation steps are carries on the same models, which avoids mistakes caused by model implementation.