A method for weighing and portioning items utilizing a robot device. The robot device includes a grip, e.g., a suction cup, to remove an item from a delivery station to a receiving area for placement into a particular batch. The method involves placing the items at delivery station according their weight and the weight of items already moved to a receiving area, selecting the items for a batch from the combination of items available for movement to the batch, and selective batching of the items in weight-determined and, optionally, type-determined groups.