The research on operator attention
Sustained attention on video monitors degrades sharply after 20–30 minutes. NPSA and academic research (Hodgetts & Chandler) both support this.
Practical monitor:operator ratios
4–8 monitors is a practical ceiling; some control rooms run higher on assist mode. Never accept 'as many as fit on the wall'.
Rotation and breaks
Rotate operators between monitor walls and other duties every 30 minutes. A 15-minute break every 2 hours is a minimum.
Video analytics
Analytics (motion detection, line-crossing, loitering) reduce load but add false positives — operators still need to verify.
Staffing arithmetic
Do the maths per shift: cameras × monitoring density × alert volume ÷ operators. If the number sits above 1.0 sustained, the design is failing.