A couple of years ago all started with the first measurement of anisotropies and edge stress as well as the detection of White Haze and other glass imperfections right after the furnace. These informations, coming directly from the on-line quality control of the tempered glass, reflect the actual production quality and are an optimal complement, which can be used next to the pre- adjustments of the regular furnace control. Having the measurement results was the first step. The furnace supervisor could now use his / her experience for a good interpretation of this additionally gathered information to optimize the furnace processes. The second step is now to use the results taken from the glass on the furnace bed and match it to the furnace structure (heating elements or quench etc.). Having these informations, a much quicker response with a higher accuracy for improving furnace parameters will become possible. And with that the delivery quality. The final step will be the closed loop between the measurement results and the furnace control for a direct readjustment of the sensitive furnace parameters.