The aims of this study were to use the operant supervisory taxonomy index (OSTI) with self-recorded videos: 1) to assess three crucial supervisory behaviours at recurrent workplace meetings; 2) to assess an intervention to increase supervisors' use of performance consequences; 3) to demonstrate how using OSTI with video for studying supervisor-employee interactions contributes to the field of human factors and ergonomics. Eight supervisors at a technical company video-recorded themselves at standardised daily staff meetings for ten weeks (360 videos, in total). All supervisors increased their delivery of performance consequences per meeting after participating in weekly sessions focusing on their use of this behaviour. The use of the crucial supervisory behaviours varied within and between supervisors. A combination of self-recorded videos over time and OSTI is a useful method for objectively analysing supervisor performance in detail and can contribute to improving supervisory behaviours and their impact on performance and health.