Web-based collaborative

The opportunities offered by Internet technologies have resulted in numerous new types of applications, among which collaborative systems. Collaborative systems are distributed multiple-user systems that are both concurrent and synchronised. During a collaborative session, several users are connected to each other in order to perform activities, such as design or evaluation, together. Several techniques for interaction with feature models, ranging from display of sophisticated feature model images to interactive selection facilities, have been implemented in webSPIFF, a new web-based, collaborative modelling system. webSPIFF is based on the multiple-view feature modelling system SPIFF. In particular, attention has been given to the maintenance of model data at the clients, and their effective utilisation for enhancing user interaction and collaboration. All real feature modelling computations are executed on a central feature model, maintained at the server computer. A session manager on the server acts as an intermediate between the SPIFF modelling system and the web clients that remotely operate the modelling system. Distribution of functionality between the server and the clients has resulted in a well-balanced web-based, collaborative feature modelling system. On the one hand, the server offers the full functionality of the original feature modelling system. On the other hand, all desirable interactive modelling functionality is offered by the clients. A good compromise between interactivity on the clients and network load has been achieved. ii Preface This thesis contains a description of webSPIFF, a new collaborative, web-based feature modelling system. I have developed webSPIFF as the final part of my graduation project. The graduation project was performed at the group Computer Graphics and CAD/CAM o