The procedures to first analyze the situation and document the safety requirements (Analysis Phases). Then, translate these requirements into a documented safety system design, using appropriate software and hardware subsystems and design methodology (Realization Phases). Next, evaluate the system against the required integrity and reliability specifications and modify it as needed. Finally, operate and maintain the system according to accepted procedures (Operation Phases), and document the results to insure that performance standards are maintained throughout the system’s life. See 61508 and 61511.