A manufacturer and retailer, which supply and sell articles such as business expendables or the like, stock articles in considerable quantities in their warehouses. However, such stocks are not always appropriate due to diversity of articles and difficulty in demand prediction, and articles cannot be delivered in a short term. A main server controls stock reserve of a branch warehouse on the basis of the check result of the urgency level of received order information, which is received from a user's information processing apparatus via a communication line, and the comparison result between the order quantity indicated by the received order information, and a non-reserved stock quantity.