Electronic marketplace (EM) has been considered as an alternative coordination mechanism to coordinate supply chain activities between suppliers and buyers. In business-to-business (B2B) electronic commerce contexts, new functional relationships have been created between suppliers and buyers in an attempt to reduce lead times and stock outs and to improve the level of customer service. In this paper we develop an ebased supply chain model and an agent for designing mass- customized online services. A new model of information flows with fuzzy logic is also suggested with a goal to achieve highly improved performance for logistical management with non-quantifiable parameters. We extend our discussion to the new role of an agent and information in supply chain activities. Information reduces the level of uncertainty which both suppliers and buyers face with. It also provides reliable and dynamic activities streamlined to supply chains of high performances. We employed heuristic approach to develop a theoretical model. Future research can analyze empirical outcomes of the application of our model.