[thelist] Item Description Field

Luther, Ron Ron.Luther at hp.com
Wed Jul 23 08:16:49 CDT 2008


Marc Cantwell asked about BOM database structures:


>>I am trying to figure out how to design a database that has items that contain other items


Hi Marc,


Bill Of Material designs can be hard to work with. (Personally, I find them to be a PITA.  I generally have better luck writing my own recursion logic in a procedural language than in trying to use the 'native' tree commands (if they even exist) in whatever database you will be using.)

The data structures aren't too bad:


BOM STRUCTURE TABLE
Part_No --- Parent_Part_No -- Qty_Per
-------------------------------------
111             null                    null
222             111                     1
333             111                     2
444             333                     2


PART NUMBER REFERENCE DESCRIPTION TABLE
Part_No --- Desc
-------------------------
111             Wagon Bed
222             Handle
333             Axle
444             Funky Sprewell-esque 'Spinner' Wheels


That's the easy part.  Taking that information and figuring out that you need 4 wheels in stock in order to build your wagon is the tricky part.

[Well okay, at least until you get into the joys of optional subassembly features, flexible configurations, substitute parts, calling out MFG step instructions specific to the selected config, completion time estimates, force & capacity planning, pegging, ...]  Welcome to manufacturing Marc!  ;-)


Good Luck!
RonL.



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