Multiple assignment of component types to feeder slots on automated printed circuit card placement machines

This paper investigates the benefits of allowing specific component types to be assigned to more than one feeder location on a printed circuit card automated placement machine. Until this experimental work, no known study has ever reported the relative improvement in cycle time when multiple assignment of component types is allowed. An experiment was designed to find the card specifications and machine operational characteristics under which the benefits of multiple assignment would be most advantageous. An integer programming heuristic was used to solve industry representative data sets for a variety of operational characteristics. For these data, it was found that multiple assignment of component types could reduce cycle time. Over all operational scenarios considered, an approximate 8% reduction in cycle time could be realized by allowing multiple assignment of component types versus not allowing multiple assignment. For those operational scenarios found to be most benefited by multiple assignment, such as card type families with a high coefficient of component variation, allowing multiple assignment across machines showed reduction of the cycle time by approximately 15% versus the alternative where no multiple assignment is allowed