Abstract
Equipment service increases in which venders have equipments in place of users and receive charge corresponding to effect of use. In this service business, income of venders change by performance that how users operate motors. To promote the business safely, a method of selecting plants where equipments are introduced is necessary, not only increasing expected earnings but also decreasing width of the earnings change. In addition, venders should negotiate interactively with users, so a method of selecting plant combination in a short time is necessary. In this paper, we propose the method for selecting plants combination considering the correlation between plants and using branch and bound approach in short time.