Case Study: Reducing risk on a mine site by optimising shift duration

Drivers moving from 8-hour to 12-hour shifts were less drowsy!

A large Brazilian mine evaluated the outcome of changing its truck drivers from working 8-hour shifts to 12-hour shifts. Optalert analysed the data from its fatigue management solution to assess the impact on driver drowsiness. Read on to learn how we reduced risk by 40% with no added cost.

The main objective of the study was to compare the drowsiness levels of operators for the 8-hour and 12-hour shifts using in-field data collected by Optalert’s Eagle Industrial early-warning drowsiness detection system.

Assessment Period
8-hour shifts
182 days
12-hour shifts
102 days

Over 284 days of assessment, we determined that drivers moving to a 12-hour shift had a 40% reduction in drowsiness. However, the 8-hour shifts involved cycling each driver through different shift times in the day, so they were constantly adjusting their sleep patterns. In contrast, each driver in the 12-hour shifts either worked the day or night shift, so no sleep adjustment was required.

Data from Optalert’s proprietary validated Johns Drowsiness Scale (JDS™) showed a significant reduction in the risk profile of the 12-hour shift rotation compared to the 8hr shift (see graphs below). In addition to the group-level data in the charts shown, the data also quantified how individual drivers responded to different length shifts and enabled the assessment of individual suitability to work longer shifts or night shifts.

Group-level frequency of alerts for each shift

Frequency of alerts generated per hour of the day

Because this mine site has an objective biomarker that measures impairment from drowsiness, it unlocks the ability to manage risk with far greater control. The impact of any operational changes are quantified.

That knowledge is then used in a cycle of continuous improvement to reduce risk and increase operational efficiency at this mine and other mines in the region.

Contact Optalert to discuss how we can give you the data you need to reduce operational risk and increase efficiency.