Graph transformation with variables for formalizing delegation authorization of workflow

Using graph transformation with variables yields very expressive rules that are still comprehensible. After reviewing the basic notations of graph transformation with variables, this article presents specification formalisms for workflow delegation policies using graph transformation with variables. In this research, authorization states are represented by graphs and state transition by graph transformation with variables. The proposed formalization provides an intuitive description for the manipulation of graph structures as they occur in workflow delegation and a precise specification of consistency conditions on graphs and graph transformations. We specifies a type graph to represents the type information in the graph transformation for workflow delegation, a set of rule schemes to build the system states and sets of positive and negative constraints to specify wanted and unwanted framework. Using formal properties of graph transformation, it can to detect inconsistencies between a rules and a constraint and lay the foundation for their resolutions. We present an algorithm to automatically check and eliminate conflicts between rules and positive and negative constraints.