Unreliable system may cause many unexpected direct and indirect losses. This could be due to accidents, penalties for late delivery, defected products, stoppage time, labors’ health and machine breakdown. Both human abilities and machine capabilities play important role in an integrated manufacturing system. Each of them has its own work rules, potentials and limitations. The total effectiveness of the system is determined by the extent to which operator and machine characteristics, both limitations and potentials, are identified and considered when judging the system. This book introduces a suggested procedure to calculate Integrated Human-Machine System Reliability (IHMSR) considering both human and machine roles and reliabilities. To do this an extended approach is described which is based on calculating the overall system reliability through integrating human reliability (measured using work performed, success rate and wasted time) and machine reliability (measured using production rate, Mean Time Between Failures (MTBF), Mean Time To Repair (MTTR) and number of defectives). Reliability Block Diagram (RBD) is used to define human-machine interaction then IHMSR is calculated.