Mine development is the process of constructing a mining facility and supporting infrastructure. In the mining industry, operations are sequential. It means one function cannot start until its preceding operation has been completed. Hence, a delay in any operations results in an overall delay for the total target. Effective underground mine planning aims at least idle & breakdown time. One such delay examined here is the cycle time for the developments in headings and drives. In this study, Blast-to-blast cycle time was evaluated in terms of productive and unproductive work in Indian underground metal mines. The actual Average Cycle Time for blast-to-blast operations was observed at 37.12 hrs, higher than the expected Cycle Time, i.e., 12.16 hrs. The variation in cycle time leads to the delay. Therefore, a study was carried out to determine the actual cause of delay through real-time analysis of all the operations during the development. The delays were breakdown, manpower idle time, shift problem, poor ventilation, water pressure problem, etc. reduced work time utilization, dewatering, and pump breakdown were observed as significant factors for cycle time delays. Effective measures were suggested to optimize the cycle time by controlling the factors responsible for the delay and improving the development cycle. Manuscript profile