Control-Flow Semantics of Use Cases in UML

The control-flow for five kinds of use cases is analysed: for common use cases, variant use cases, component use cases, specialised use cases and for ordered use cases. The control-flow semantics of use cases - and of the uses-relation, the extends-relation and the precedes-relation between use cases - is described in terms of flowgraphs. Sequence diagrams of use cases are refined to capture the control-flow adequately. Guidelines are given for use case descriptions to attain a well-defined flow of control