Analysis of Truck Downtimes Using Log Dispersion Plot

It is becoming increasingly clear that improved equipment availability is a key to optimising return on mine investment. Well-maintained equipment is safe and provides reliability to protect the operator as well as the equipment. Unplanned downtimes conflict with this maintenance function and result in costs to a mine in various causes. To minimise the occurrence of unplanned downtime, data should be recorded in logical and easily understood format which will enhance management decision making. This paper uses log dispersion plot to analyse downtimes of a fleet of 22 dump trucks from the Nchanga Open Pit, Zambia over a period of two months. Downtimes were categorised into breakdown codes to determine which ones were acute, chronic or a combination of both. The breakdown codes which were critical to the reduction of unplanned downtime and improvement of truck performance were prioritise.