1 Reply Latest reply on Mar 1, 2016 10:44 AM by Matthew Lorono

    Using detached Parts Lists (Recommendation in Frank B. Watts' book - Engineering Documentation Control Handbook)

    David Diehl

      I've been reading Frank B. Watts' book - Engineering Documentation Control Handbook, and in it he states that "the most prevalent mistake made on assembly drawings is to put the parts list on the body of the drawing...When the usage of computers became common, they brought a powerful capability to produce detached parts lists...The parts list should normally be on a separate detached list."


      We currently DO put the parts lists on SHEET 1 of every assembly drawing, but Frank has got me thinking.  Our top assembly drawings are massive and take a considerable amount of time to open and revise.  By having a detached parts list, one advantage could be when all we are doing is replacing an item in the parts list with another, we could potentially keep our massive 'pictorial' top assembly untouched and then only have to revise a parts list document to show the ADDED/DELETED item.  This change would take minutes versus hours since we would basically be revising a simple parts list document rather than a large CAD assembly file.


      I am curious as to how you handle parts lists.  Are they integrated on your pictorial assembly drawings or are they detached as Frank Watts is suggesting?  And how is it working for you?


      Thank you in advance.

        • Re: Using detached Parts Lists (Recommendation in Frank B. Watts' book - Engineering Documentation Control Handbook)
          Matthew Lorono

          There are many ways of handling separate BOMs.  It all depends on your system.  One might question whether top level assembly drawings are necessary at all, particularly if you have well detailed assembly work instructions, and/or if you have product configurators that build your final product based on work orders.  Many companies use BOMs on drawings, and many do not.  However, if you also have a PLM, you'd be duplicating the information (having more than one single source of information), which is a faux pas in ISO compliance.  In such a case, the BOM generated in CAD can be mapped to the PLM (where it would be further modified for manufacturing purposes), but not actually displayed on the Assembly Drawing itself.  Or, you may just create the BOM within your PLM, using the assembly as reference only.  If you don't have a PLM or ERP which maintains BOMs, then you'll likely still want to use the CAD BOM on your drawing, since that would be the only source that information would be found.  I'm not even covering all the possibilities.  There are many ways of handling this.