Coalition formation and operation in virtual organisations
The concept of Virtual Organisations (VOs) or Virtual Enterprises (VEs) is rapidly emerging as an important topic in many areas of computing including e-commerce, grid computing and the semantic Web. One reason for this interest is that VOs provide a means of bringing together a number of autonomous stakeholders in a dynamic fashion in order to address a specific problem or niche. These agents then work together for some period of time and then disband when it is deemed appropriate to do so. There are, however, many technical, social and economic issues associated with this VO lifecycle (i.e. creation, operation, maintenance and dissolution) that need to be addressed before VOs can be considered to be practicable. While previous technical work on VOs has concentrated on providing tools to support different aspects of the VO lifecycle, comparatively little work has focused on the mechanisms for automated VO creation, operation and maintenance. To address this shortcoming, this research aims to study and design mechanisms for the VO creation, operation and maintenance phases. In this thesis, our approach is to use combinatorial auctions and coalition formation mechanisms. In particular, novel algorithms for clearing multi-unit single-item and multi-unit combinatorial auctions have been developed as a means of tackling VO creation and one part of VO maintenance. A novel algorithm for coalition structure generation has also been developed to address VO operation and another part of VO maintenance.