To help disabled people to live productive lives through their own vocation, work assistive mobile robots have been developed for a real work environment. A survey in a real employment situation was carried out on how to effectively assist disabled people as many as possible. Mission statements for developing assistive robots are derived from the survey result, and work assistive mobile robot system type I and type II are developed according to the mission statements. The robots are performed user-trials by disabled people who are working in a manufacturing labor.