Nowadays, Internet-based businesses is activated in various organizations. In most of distribution and manufacturing companies, the main current of internet businesses is on-line sales (B2C: Business-to-Customer) centering around internet shopping. Most of theses businesses applied contents-centered and customer-oriented methodology for implementing internet business system(IBS). Also, recently, Introduction of Internet-based VAN(Value Added Network) systems and e-Procurement systems of purchase fields between parent companies and suppliers are proliferated for an efficiency of business and a reduction of transaction cost. These systems used methods of re-constructing the existing legacy systems into Internet-based systems. This paper proposes a customer-oriented and process-based methodology that simultaneously considers customer requirements and business processes of operational systems in order to implement an Internet business system. To demonstrate the usefulness of the proposed methodology, we applied and implemented an Internet business system for sales of A/S (After Service) spare parts and services on the object of the "H" company of manufacturing ship engines, which is a make-to-order corporation. As a result, This paper showed an effective applicability of Internet-based e-business on A/S business processes in order to improve a service quality for customer satisfaction in manufacturing companies.