How should usable pan diameter be evaluated when buying an automatic cooking machine?

Usable pan diameter is not the outer rim figure. Work back from batch loading, how far ingredients spread, and the tossing trajectory to find the circle that actually holds and moves food. During a trial, cook your heaviest menu item repeatedly, weigh each batch, time the output, and scrape and weigh pan residue; heavy leftovers or food stranded at the edge mean the usable diameter is too small. Put that figure and its pass limit in the technical agreement, filed with the acceptance report so any replacement model can be retested against it.