Systems and methods for estimating a copy sheet supply in a printer. Pre-event and post-vent signal patterns are compared and analyzed to produce an event characteristic which distinguishes the faulted feeder and the faulted phase. The playard includes two retainers, each mounting on the second side rail of the frame body. Unexpected changes of the time and loading schedules can be balanced and their negative impact on just in-time delivery of goods can be lowered.