N. S., N.S.Choudhary, R.P.Murthy, C.S.N.2026-02-052020Safety and Reliability, 2020, 39, 46115, pp. 215-2299617353https://doi.org/10.1080/09617353.2020.1759260https://idr.nitk.ac.in/handle/123456789/24104In a surface coal mine, efficient usage of shovels and dumpers should be most reliable and available to reach their production target. Keeping this in mind, this study was carried out at a surface coal mine, which is located at Open Cast-I, The SCCL, Kothagudem area, Telangana. The mechanical failure data such as time between failures (TBF) and time to repair (TTR) of each sub-system of a shovel-dumper system were collected and analysed statistically and graphically for reliability and availability. Graphical methods such as trend test and series correlation test and Chi-squared test were used to validate the independent, identically distribution of mean time between failures and mean and time to repair for the same a shovel and dumpers. Statistically, the Weibull distribution is selected as it was found the best-fit distribution by the Kolmogorov-Smirnov (K-S) test using Isograph Reliability Workbench. In K-S test, it was found that shovel KS1 has reliability of 0.2682 and dumpers BD1, BD2, KD2 and KD4 had reliability of 0.3731, 0.2850, 0.2897 and 0.2962, respectively for the 1 year of working hours. Also, calculated reliability- based time interval for preventive maintenance to achieve 70, 80 and 90%, respectively of reliability for same shovel-dumper system. © 2020 Safety and Reliability Society.Chi-squared testKolmogorov-Smirnov testSeries correlation testWeibull distribution