In this paper, we present the rationale and the baseline of a notation which can be used on its own or as an extension to standard UML to facilitate specification of an interactive system’s global execution context (GEC). The GEC graph is a visual construction consisting of (a) nodes, which represent interaction scenarios, and (b) directed links, which represent scenario relationships designating alternate execution, concurrency, ordering, and set-oriented relationships between two scenario nodes. The technique is particularly useful for specifying adaptable and adaptive behaviours across interaction platforms, contexts of use and target user communities. In the paper, we demonstrate the application of the technique using a file-exchange application which runs on a portable device such as a PDA and implements a lightweight ftp process to connect to a server wirelessly and offer standard ftp functionality (get/put/delete).