A preliminary inquiry on the process of work such as carrying or setting up large-sized equipments for constructing new electric power plants is indispensable for assuring efficient works and safety operations.
We have been developing a computer aided beforehand-study system which assists unexperts who has not much experience about constructions of electric power plants.
In this paper we propose an automatic search algorithm on suitable routes for carrying in electric power facilities; it works as function of the system mentioned above. In the algorithm the automatic route search algorithm for autonomous moving robots and manipulators is improved to fit the construction of electric facilities; the new algorithm can find not only one route but also some candidate routes and take care of the workers' space around the moving equipment.
The proposed algorithm has been applied for examining the process of transformer installation work in a substation.