کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
807929 | 1468240 | 2014 | 8 صفحه PDF | دانلود رایگان |
• In this paper the redundancy allocation problem (RAP) for a series–parallel system is considered.
• Traditionally there are two main strategies for redundant component namely active and standby.
• In this paper a new redundancy strategy which is called “Mixed” redundancy strategy is introduced.
• Computational experiments demonstrate that implementing the new strategy lead to interesting results.
Traditionally in redundancy allocation problem (RAP), it is assumed that the redundant components are used based on a predefined active or standby strategies. Recently, some studies consider the situation that both active and standby strategies can be used in a specific system. However, these researches assume that the redundancy strategy for each subsystem can be either active or standby and determine the best strategy for these subsystems by using a proper mathematical model. As an extension to this assumption, a novel strategy, that is a combination of traditional active and standby strategies, is introduced. The new strategy is called mixed strategy which uses both active and cold-standby strategies in one subsystem simultaneously. Therefore, the problem is to determine the component type, redundancy level, number of active and cold-standby units for each subsystem in order to maximize the system reliability. To have a more practical model, the problem is formulated with imperfect switching of cold-standby redundant components and k-Erlang time-to-failure (TTF) distribution. As the optimization of RAP belongs to NP-hard class of problems, a genetic algorithm (GA) is developed. The new strategy and proposed GA are implemented on a well-known test problem in the literature which leads to interesting results.
Journal: Reliability Engineering & System Safety - Volume 130, October 2014, Pages 132–139