The big customer order is coming together quickly. Just a few more assemblies need to be put together. The team will then package them for shipment. Finally, we wait for the trucks to arrive and celebrate another tough but successful on-time project shipment, or so we think.
“Hey boss, we are short some items. We got some extra stuff too. Can you help us out?”
That important project will not be ready in time. Why you wonder? You have just discovered a bill of material error.
Bill of material errors can be major or minor. Lets now look at some of the more common errors, the impact they can have on a manufacturing company and the ways to avoid them.
Wrong Item is on the BOM: This is actually two errors for the price of one. What should have been on the BOM is missing and something that should not be on the BOM is present. While you are expediting the missing item, you have the less urgent task of returning the wrong item and potentially incurring a restocking fee. This all can be avoiding by auditing BOMs prior to input into your ERP system. Get a second person to check the work. Really smart and talented people make mistakes-try to catch them before they become costly mistakes.
Item Omission: This is a tricky mistake to catch. How can you know what is missing on the BOM if you have never built to product before? Well that is the key-build it before you build it for real. Prototyping, alpha builds, reverse engineering, test builds, demo assemblies-all of these approaches are ways to proof product BOM structures. I once spent the first three months at a new job reverse engineering products in order to create the bills of materials. After that, I enlisted help from the designers to have them build their own designs using the preliminary BOM as the parts pick list. This is a very effective method of checking BOMs for accuracy.
Unit of Measure Error: How much do you need to build the product? You answer “Five”. My reply-“Five what?” is my reply. Unit of measure can be any of the following: inches, feet, pounds, cubic liters, pair, gallons, sets, kilograms, kits, linear inches, square yards, tubes, and so on. Without an accurate unit of measure, a BOM is useless.
MRP Needs Accurate BOMs: Material Requirement Planning requires BOM accuracy to correctly plan all made and bought items required to satisfy customer requirements. You may have heard that MRP does not work well. I will let you in on a little secret friend. That statement is an indicator of a business with BOM errors. Improve the accuracy of your BOMs and your production buyers and planning will be very grateful for the effort.
Second (and third) BOM Usage Errors: Once a BOM error has been uncovered, fix it. Fix it at the moment of discovery. Do not hesitate. Few things are as frustrating in the manufacturing world as solving a problem multiple times.
Get that BOM squared away and the important customer project finished and loaded on the truck. Next time avoid the stress and fix the errors before they become a headache.
I have personally experienced all of the above over many years of making mistakes and learning from them. That makes me an expert!