A new type of pallet stacking assembly line. Two pick-and-place robots are used. The first robot has a relatively low position. The second robot is in an elevated position. A pallet dispenser dispenses a first pallet onto a pallet conveyor. The pallet conveyor then moves the first pallet to a first build position in front of the first robot. The first robot then begins picking products from a first pick position and stacking them on the first pallet. Once the products on the first pallet reach approximately half the finished height, the pallet conveyor carries the first pallet over to a second build position in front of the second robot. At the same time, the pallet dispenser dispenses a second pallet which is carried to the first build position. The second robot picks products from a second pick position and places them on the upper portion of the first pallet in order to complete the stack. Meanwhile, the first robot is picking and placing products on the lower portion of the second pallet. The process continues indexing, with both robots ideally being busy all the time. Each robot only has to build half the pallet. Thus, overall line speed is increased.