Driven by the fast changing service demand-and-supply requirements, virtual organisation alliances are created to adapt highly dynamic B2B collaborations. However, the temporary partnership and low trustiness between collaborating organisations raise challenges to effectively manage collaborative business processes. This paper presents an approach on the basis of a service oriented relative workflow model to support virtual organisation alliances. This approach takes an organisation centred design method and deploys a visibility mechanism to provide a finer granularity of authority control at contracting and collaboration design phases. The open contracting and inter-organisational collaboration design in a virtual organisation alliance are particularly addressed and discussed in this paper. .