Abstract. To remain competitive, enterprises have to mesh their business processes with their customers, suppliers and business partners. Increasing collaboration includes not only a global multi-national enterprise, but also an organization with its relationship to and business processes with its business partners. Standards and technologies permit business partners to exchange information, collaboration and carry out business transaction in a pervasive Web environment. There is however still very limited research activity on modeling multi-party Web-based business collaboration underlying semantics. In this paper, we demonstrate that an in-house business process has been gradually outsourced to third-parties and analyze how task delegations cause commitments between multiple business parties. Finally we provide process semantics for modeling multi-party Web-based collaborations.