Reliability and availability analysis of a robot-safety system

Purpose - The purpose of this paper is to study reliability, availability, and mean time to failure of a repairable robot-safety system composed of n robots, m safety units, and a perfect switch. Design/methodology/approach - Generalized expressions for system state probabilities, system availability, reliability, and mean time to failure are developed. Supplementary variable and Markov methods were used to develop these expressions. Findings - This study clearly demonstrates that backup robots, safety units, and the repair process help to improve system availability. Practical implications - This study will help maintenance engineers and reliability practitioners to become aware of the combined effect of backup robots, safety units, and the repair process on the performance of the robot-safety system. Consequently, they will make better maintenance related decisions in organizations that make use of robots. Originality/value - This paper has studied the effects of having redundant robots, safety units, and the repair facilities on the performance of a robot-safety system with perfect mechanism to turn on a safety unit. This is one of the first attempts to study the combined effects of all these factors on a robot-safety system.