Optimization programs, full-profile scanning, and powerful computers used with auto-rotation systems make thorough log rotation, log positioning and sawing decisions possible. However, high log throughput, bumpy log surfaces, and heavy sawlogs make accurate mechanical execution difficult. How accurately can auto-rotation systems execute thorough log rotation and log positioning decisions? Two mill tests were carried out to estimate rotation errors and unintentional log movement. OPTITEK®, Forintek's log breakdown simulator, was used to analyse the effect positioning errors have on the economic benefits of auto-rotation systems.