First In First Out (F.I.F.O.)
A system for keeping track of the order in which information or materials are to be processed. The goal of FIFO is to prevent earlier orders from being delayed in favor of newer orders which would result in increased lead time and unhappy customers regarding the earlier orders.
Note: FIFO can usually be implemented in a very straightforward fashion and makes a good deal of sense on an intuitive and practical level. Where FIFO falls short is the shortcomings and emotional decisions made by humans to circumvent the system. Customers that are considered more “important” than others test the will and commitment of even the most stalwart FIFO advocates.