Investigating Standby from a System Reliability Perspective

The interest on standby approaches, policies and related issues is strongly increased in last years with the growing awareness of environmental and energy problems and challenges. Their success is also motivated by the cost benefits they ensure. In order to properly design such systems adequate techniques and tools allowing to quantitatively evaluate the underlying phenomena are required. In particular, different aspects and perspectives have to be considered, overcoming the lacks of current literature. The aim of this paper is to provide an analytical framework for the in depth investigation of standby system reliability and availability. In particular the problem is addressed from two different point of views, separately observing the effects of standby management into the system in isolation and when it is plunged into the environment. In the paper, starting from the dynamic reliability theory, a formal characterization of the problem and its mathematical formulation are provided into an analytical framework, then used in the evaluation of standby redundant systems and their management and configuration. The effectiveness of the technique proposed is demonstrated through a numerical example comparing different solutions.