UML Analysis Using State Diagrams

This article demonstrates a new approach to analyzing UML designs using state and sequence diagrams. From multiple state diagrams, a super-state diagram which includes the cross-product of the selected states is built along with a transition matrix of possible transitions. The closure of the transition matrix is used to identify unreachable states and impossible transitions. Additionally, the closure is also used to evaluate consistency between the state diagrams and the sequence diagrams. Missing and impossible sequences can be identified. A prototype tool has been built to calculate the closure of the transition matrix and to compare the results with the sequence diagrams.