Overseas sales of multi air-conditioners for commercial use are increasing exponentially. There is now a strong demand for technical and service guidance on the latest products from the local stores selling and servicing the air conditioning equipment produced by Mitsubishi Heavy Industries, Ltd. (MHI). To meet this demand, MHI has developed a service operation assistance system (MASA system) based on IT. To increase its service-processing capacity in the Chinese market, MHI has established a service network made up a control service store for each region, a set of sales and service stores working under each control store, and the MHI service center working as the key component at the core of the servicing network. The MASA system supports the operation of this service network.