A survey was made on the following themes to be appropriately applied to the expert system for the office work in the electric power company: business-related themes to support the dealing with clients, accumulation of basic business know-how and retrieval of detailed charges. General-affairs related themes to support the consultation about the stock and compensation for the damage, and business procedure in the company. The application of expert systems which are common to all the themes aims at the four items which are accumulation and common application of business know-how, business progress management, educational support, and self-enlightenment. It is important to clearly comprehend those items for establishing the expert system. The needs-related concept and efficiency-related concept are called for in the selection of themes. The former concept covers the service improvement, business efficiency heightening, resources saving and degree of needs, while the latter does the degree of generalization, management unification, accumulation of know-how and experience, degree of appeal, and educational support. The model system must be experimentally built for the execution. 2 refs., 7 tabs.