It has been an increasing trend for companies to migrate their businesses onto or publicize themselves on the Internet. Business process reengineering (BPR) is applied to migrate the business processes of the supply chain onto the Web. Such migration may cause some of the processes merged together, minimized or transformed into other processes within a supply chain. Therefore, careful planning for such migration with technical requirements is necessary. This paper starts with the review of related research on BPR, migration of supply chain onto the Internet, and the impact analysis of the migration. A thorough overview of how BPR can change each process of the supply chain onto the Internet is discussed. The main contribution of this paper is a framework of the electronic commerce (EC) impact on the supply chain and the measurement of impact. An industrial example is used to illustrate the evaluation as a result of EC deployment.