Extranets as they have come to be termed are revolutionizing supply chains and their management. Companies and organizations with quite different internal information systems can now access data from other supply chain members. The purpose of this study was to determine what is the actual condition for completing a company's extranet project successfully because only that can enable the realization of supply chain improvements. How to make employees and customers adopt this new extranet and so that they will start to use it actively in their daily activities? Based on previous studies, observations and interviews, an expectations theory was built. According to this theory user’s realistic and accurate expectations make a good foundation for accepting a new information system. If the user’s expectations are fulfilled, user will perceive the new system easy to use and useful which on the other hand leads to acceptance of the system. This expectations theory can be used as a starting point for almost any information system implementation where user acceptance is considered critical.