FAQ : Should an item be put on the master schedule before it has been fully designed?

The latest you can leave adding an item to the master scheduled is when you need to order components for the product. The more visibility you can provide your purchasing people, the better prices and the more reliable delivery will be so you should add a product bill of material as soon as possible, with the best information available, even if it is not complete. It is also important to put an item on the master schedule, complete with its bill of material and routing, when you need to know if you have sufficient capacity to manufacture the part.

Getting parts you have made before onto the master schedule should not be difficult. If you are in the business of engineering parts to order which are variations on a standard range of products, we suggest you put a tentative or generic bill of material onto the planning system as soon as you have a required shipment date or even a target shipment date. The generic bill will have proper part numbers and estimated lead times even though many of the parts have not been designed or specified. In the early stages the bill is in a fluid state and may be changed by the design department at will. Once you reach the cumulative lead time, the design is frozen. Changes to frozen bills must go through the engineering change order process as outstanding orders may be affected.

Getting the technical departments to understanding the vital importance of the bill of material for a manufacturing company is never easy. It is often easier for outsiders to get this message across (see BOM courses).

Phil Robinson - www.bpic.co.uk
BPIC - your manufacturing planning resource