Grey Uncertainty Technique in the Calculation of Maintenance Activities’ Standard Time

Since the beginning of the Iran Islamic Revolution, Iranian organizations and manufacturing institutions have gradually been able to internalize significant parts of their maintenance and maintenance activities. One of these companies and institutions as the first producer and exporter of copper in Iran is Sarcheshmeh Rafsanjan Copper Complex which is affiliated to the National Iranian Copper Industries Company. Based on the performed studies, it has been determined that this company, considering the internalization of maintenance of many parts, has not done any activity in two areas of recording and sharing the knowledge gained in the field of maintenance and recording the duration of maintenance activities to calculate the standard time related to those activities. Therefore, in this research focused on one of the most important maintenance activities of this complex regarding one of the key and vital parts that has the capability to share the acquired knowledge with other organizations and institutions in the same field from two aforementioned areas. In this regard, in order to conduct this research and due to the specific uncertainty regarding the maintenance activities, gray uncertainty in the analytical timing method has been used to calculate the standard time. Finally, the results of this study showed that performing maintenance activities takes a significant amount of time from the production scheduling, and the duration of maintenance activities should be considered in order to perform all planning, especially operations management.