1. A computer-implemented method of sequencing items for absorption costing, said method comprising: creating an initial hierarchy comprising said items; modifying said initial hierarchy using an iterative process to reposition a plurality of said items, wherein said iterative process generates a modified hierarchy and comprises: accessing one of said items; identifying a plurality of children items of said accessed item; and moving said accessed item to a hierarchy level above a hierarchy level containing a plurality of said children items; repeating said modifying until an iteration is completed without repositioning any of said plurality of said items; and determining an absorption costing sequence for said items from said modified hierarchy.