COMMODITY SALES METHOD AND COMMODITY SALES SYSTEM

PROBLEM TO BE SOLVED: To predict the time of a customer requiring a commodity or part to early and surely make a proposal. SOLUTION: A recommended combination of the parts or expendable supplies constituting a commodity delivered to the customer is preliminarily prepared every commodity for a part group of an influenced range every generable obstruction or superannuated part within the range capable of ensuring the connection between parts. The time requiring a replacement or supply is calculated from the accumulated maintenance cost of the commodity every customer or the lifetime and mean time between failures every trouble of each part constituting the commodity to predict an optimum proposing time, whereby the commodity, parts and expendable supplies are automatically proposed. The customers are classified to continuously ordering customers and other customers, the proposing method of commodity is varied between the both, complimentary services are proposed with the proposing method of commodity varied between the both, respectively. A discount price is calculated and presented to the continuously ordering customers to urge them to early perform the replacement of the commodity or parts and the supply of expendable supplies.