The algorithm of customer demand decomposition suggested by this study is a reconstruction method of distribution network under the allowance of same level supply. Regional distribution center(RDC) distributes additional inventories of some of the supplying items to retailers under its charge to reduce the time needed for emergency delivery to neighborhood retailer where backlog happened. This also restrict the purpose of the inventories held by RDC as only regular supply. All of which leads to the creation of more realistic method allowing the affiliation of closing related RDC with one in the vicinity. In this study, the role of RDC is restricted only as supplying items regularity and the conruction of distribution system processing through the closing by consideration of the possibility of supplying retailers from the RDC in the vicinity is discussed.