Reliability Analysis of 3-State Systems

This paper describes a reliability analysis of a system where its components take one of three states-good, degraded, or bad. For this 3-state system, the analogy of 2-state system is investigated. The calculation of system reliability can be reduced to that of the reliability of a corresponding 2-state system, provided that it is a generalized S-P system, with or without artificial, degraded components. Consequently, methods for evaluating the exact system reliability and useful bounds on system reliability of 2-state s-coherent system directly apply to 3-state systems. Some basic properties of system reliability with s-independent components are then presented. Further, some reliability bounds on systems with s-associated components are derived. Finally, the method is extended to multi-state systems. This state reduction can be used somewhat in analyzing models where time plays a role.