The present invention aims to prevent an oversight in an association between items in a deliverable, and to detect an error in the association early. An item designation unit designates a plurality of items to be included in a generation target deliverable, before generation of the generation target deliverable being a deliverable to be generated. An item association unit associates, before generation of the generation target deliverable, a plurality of high-order items included in a high-order deliverable with the plurality of designated items designated by the item designation unit. The high-order deliverable is a deliverable of a higher stage than a stage to which the generation target deliverable corresponds.