Translating UAN into CSP

We define a translation from the User Action Notation (UAN) to the process algebra Communicating Sequential Processes (CSP). UAN is an informal notation, used for task modeling and design. Translating a UAN task description to CSP provides a base for rigorous development of an interactive system. The resulting CSP description is a suitable abstract starting point for development, as it describes externally visible behaviour with no mention of presented or underlying state. Our translation covers all UAN constructs except for waiting, interruptibility and true concurrency which cannot be expressed in interleaving, un-timed CSP. Our approach integrates task models, typically based on user-oriented concerns, into rigorous development which is typically system-oriented. It provides a bases for a framework for formal development of interactive systems