Creating and documenting multi-level bills of materials; documenting and authorizing engineering revisions of parts and bills of materials; recording and documenting Engineering Change Orders (ECO) for parts (including attachments); reasons for changes and authorizer rounds as part of each part’s engineering control; an array of reports regarding parts and bills of materials (including a “Where Used” report and a graphic interface for the display of multi-level bills of materials). This module as an add-on does not allow the industrial application of bills of materials, such as MRP or work order planning, which appear only in the manufacturing package.