In this paper we present a B2B integration project, which aims to augment the added value of services instead of improving efficiency by automating processes. This paper introduces the VAlue Layered docUment Exchange (VALUE) model, which is a novel collaboration model adopted for this project. The key feature of the VALUE model is that partners exchange XML documents that are updated by adding elements for process information, such as the acceptance or rejection of a proposal, to received documents. Exploiting the extensible characteristics of XML, this model enables real business collaboration without complex process flow control. The project has demonstrated the advantages of a collaborative protocol based on this model in the Japanese retail industry. This protocol adopted ebXML MS (Messaging Service) for messaging over the Internet, and was the first case that applied ebXML to real business collaboration in Japan. Keywords B2B, ebXML, supply chain management.