[en] Each year, maintenance work is carried out for about 10,000 pieces of equipment, including mechanical devices, electric equipment and instruments, at the Tokai Reprocessing Plant. Ninety percent of such maintenance work is preventive maintenance. In order to manage the information about the maintenance work, a computer support system was developed between 1985 and 1992. Twenty-seven thousand pieces of equipment and 180,000 maintenance histories have already been registered in the system. The system has been used for planning inspections and replacement of equipment as well as checking their maintenance histories. Actual usage of the system has shown that some auxiliary functions need to be added. The system will therefore be improved and extended. (author)