E-business is developing very rapidly as a new way of working. It brings some advantages for production-inventory management. Despite its great impact, research on the influence of e-business on production-inventory systems is very rare. In this paper, we first study those aspects which are affected by e-business-based customer ordering systems and then influence production-inventory systems. A mathematic model is then presented based on an assumption of simple e-business model of direct sales channel. Discussions are given on issues related to the system.