The automatic failure recovery of assembly tasks in robot workcells is discussed. An efficient scheme for the design of autonomous workcell system management systems is presented. In this approach an online management system performs two functions: task scheduling and task execution control (the latter embeds failure recovery). Task execution control is decomposed into three functions: monitoring of tasks, failure analysis, and recovery. Methods of designing the modules that perform these functions are presented. Failure detection is performed by a sensor-based monitoring module, failure diagnosis is performed by a rule-based failure analysis module, and failure recovery is accomplished by a two-level recovery module. >