Reliability and Maintainability Analysis for Multiple Repairable Units (Case Study: Sungun Copper Mine)

Assessing the reliability engineering of loading and bearing machines of Sungun copper mine, taking into account the environmental conditions and risk factors involved in the working conditions of these machines, will lead to a more accurate understanding of their failure behavior and this leads to prediction of accessibility to this machines. After determining the system and subsystems of the department, the required data are collected and sorted in a 15-month time frame, and then calculate the time between failures (TBFs) and the time to repairs (TTRs) in each sub-system, including 2 loader and 8 dump truck, are. Became To this end, for all subsystems, the heterogeneity test was first applied by Stata software, and all subsystems, with the exception of 7 subsystems, including dump-truck units 1, 2, 3, 4, 5, 7 and 8 in TBFs, were considered as the not-heterogeneous. Hence, heterogeneous group was modeled by PHM which is a covariate-based model, and its reliability function was fitted. In the next step, trend tests was applied to not-heterogeneous sub-systems. those trend tests were performed by Minitab software. homogeneous sub-systems with failure trend, formed the data group and modeled with the “NHPP”. In the next step, the non-trended subsystems, formed the data group, and after applying the likelihood and correlation tests, They were modeled by the “HPP”. Thus, reliability and maintainability functions of all the groups of machines of Sungun copper mine were fitted to 95% confidence level.