Some copula-based results on optimal number of cold standby components in parallel systems

Stochastic Models in Probability and Statistics

مقالات آماده انتشار، پذیرفته شده، انتشار آنلاین از تاریخ 08 مهر 1403   

نوع مقاله: Original Article

نویسندگان

Motahareh Parsa؛ Hadi Jabbari^* ؛ Jafar Ahmadi

Ferdowsi University of Mashhad, Mashhad‎, ‎Iran

چکیده

‎This paper deals with a system's profit and efficiency functions consisting of a two-parallel components supported by (n-2) cold standby redundancy‎. ‎It is supposed that the components are not repairable and the failed component is immediately replaced with one of the cold standby components‎. ‎Because the lifetimes of active components are dependent‎, ‎their dependency is modelled by Farlie-Gumbel-Morgenstern (FGM) copula function‎. ‎Finding the optimal $n$ according to the highest profit function of the system and efficiency values is studied while the effect of the dependence parameter is considered‎. ‎It is concluded that though increasing n grants higher system reliability it is not always wise as long as the redundancy maintenance costs‎. ‎Due to the complexity of the formulas‎, ‎for the large values of n‎, ‎the results are analyzed numerically and graphically‎. ‎Finally‎, ‎some examples are given to illustrate the results‎.

کلیدواژه‌ها

‎Cold standby redundancy؛ ‎ ‎Copula function؛ Profit function؛ ‎ ‎Reliability؛ ‎System efficiency