Multimedia conferencing systems as building blocks for complex cooperative applications

Cooperative and multimedia systems together give way for powerful user-centred tools. Current software design approaches do not reflect the complexity of such applications, a new level of abstraction is required. We present Work Scenario Graphs (WSG) and Scenario Flows (SCF) for the modelling of cooperative applications. Both modelling elements cope with different types of cooperative work and can, by combining them, express a wide variety of coordination policies-ranging from implicitly coordinated CSCW style cooperation to highly coordinated workflow style. We demonstrate the usability of WSG and SCF by modelling selected multimedia conferencing systems in an abstract, easy reusable way. We therefore introduce an abstraction for video conferencing systems based on the three basic aspects: conference setup, coordination and cooperation