It is very important to finish a desired job when a robot works in a hazardous environment or when the operation is closely related with the human life, regardless of the failures of some joints. Kinematically redundant robot manipulators have failure tolerant properties inherently. So one can expect that even if failures of the joints occur, the desired job can be done if the number of failure joints are not greater than the redundancy. But there are some situations where the desired job cannot be done. The possiblity of finishing a job depends on the robot manipulator configuration at the moment when a failure occurs. Therefore, it needs to avoid the unfavorable configuration before the failure occurs. In this paper we propose two approaches that make the fault tolerant path. We will define two measures, a fault tolerant measure and a fault workability measure. Using these two measures, the fault tolerant path can be obtained.
