Redundancy allocation for series-parallel warm-standby systems

Increasing the reliability of a system is generally achieved by using redundant components, which results in raising the system cost. A great challenge in system design is to improve the system reliability while still meeting the resources limitations, typically the budget constraints. This paper considers the redundancy allocation problem (RAP) for series-parallel systems with warm standby sparing (WSP). WSP is a type of dynamic redundancy that compromises the energy consumption of a hot standby sparing system and the recovery time of a cold standby sparing system. The existing RAP solutions mainly focus on systems with cold and hot standby redundancies. This paper presents two optimization solution methodologies, respectively based on genetic algorithm and integer programming to achieve optimal design of a series-parallel with warm standby redundancy. Both methodologies are illustrated using examples.