Specification of Requirements Using Unified Modeling Language and Petri Nets

One of the major problems the software engineering is dealing with is the correct specification and implementation of requirements to the system being developed. A lot of design methods use models of the Unified Modeling Language for requirements specification and further design of the system. To validate the specification, the executable form of models has to be obtained or the prototype has to be developed. This may cause errors in the transformation or implementation process, which results in incorrect validation. The approach presented in this work focuses on formal requirement modeling combining the classic models for requirements specification (use case diagrams and class 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.