The present invention generally comprises a method for achieving fault tolerance in a PV FAB. A plurality of processing tools may be coupled together along a processing line, and a plurality of substantially identical processing lines may be arranged within the FAB. Whenever a processing tool within any processing line is shut-down, rather than shut-down the entire processing line containing the shut-down processing tool, work-pieces may be routed around the shut-down processing tool by transferring the work-pieces to an adjacent processing line within the FAB. At a location after the shut-down processing tool, the work-pieces may be transferred back to the processing line containing the shut-down processing tool. During the time period that the processing tool is shut-down, the other processing lines within the FAB may increase their throughput in order to maintain a substantially constant optimum throughput for the FAB over a given period of time.