There is a box in the title block of most drawings for logging ‘Used On’ parts. Many companies make tremendous effort maintaining this box listing all of the products that use the part number. Some engineers equate ‘Used On’ with ‘Where Used’ and go the extra step of listing all of the places where the part is used; including subassemblies. Is this good practice? What is the proper use for this box?
The ‘Used On’ block box should only show the Original Product where the part is used. No attempt will be made to keep other ‘Used On’ up-to-date on the drawing. Maintaining ‘Used On’ information should be done in a separate file, MRP/ERP, or PLM.
- Rule: Do not maintain ‘Used On’ information in Design Documents; set up a separate file or system for this data.
- Reason: You may use any item over and over again in other products; it is wasteful to repeatedly revise the original document each time you use the item elsewhere.
Although it can be done, maintaining a ‘Used On’ list in an Excel file is not recommended as it can become quite complex, and eventually a burden, as your company grows. CM groups should have access to an easy-to-use information system that can maintain ‘Used On’ and ‘Where Used’. Most MRP (Manufacturing Resource Planning) or ERP (Enterprise Resource Planning) systems have these capabilities. Be careful because these systems are typically set up to facilitate production, the BOMs are typically arranged to reflect the “as built” structure. This can be quite different from the “as designed” structure originally initiated by product development. In direct BOM comparison, you may find that the part may reside in different indented levels between “as designed” and “as built” structures.
The best solution to maintain ‘Used On’ and ‘Where Used’ information with clear design intent is to use a Product Lifecycle Management (PLM) system. PLM will automatically register this information as the product is being designed or modified. Visidian PLM provides this functionality along with other tools to improve the efficiency of product data management.
CM Tips furnished by:
Frank Watts BSME, CCDM.