Abstract: A product storage and picking system having a plurality of shelves each with a front, a rear, a top, a bottom and spaced sides. The plurality of shelf units are arranged in first and second side-by-side rows with the shelf units in each of the first and second rows arranged in front-to-rear relationship. A plurality of shelf units are movable guidingly in a cycle to selectively place each of the shelf units serially at a pick position so that product on the shelf unit at the pick position can be removed to fill an order. At least one of the shelf units is movable in a predetermined manner during a portion of the cycle without moving other shelf units in the plurality of shelf units.