The Test / Rework / Scrap Cycle

If your only method of quality control is testing the finished product to see whether or not it meets the customer's specifications, then there is a good chance that some considerable proportion of the product will be non-conforming. Inspection doesn't improve the overall quality of the product, it is simply a way of weeding out bad product before it reaches the customer.

Having identified the non-conforming product, the organisation then has to decide whether it is possible to fix it by further work, or simply scrap it. All of this adds to the total cost of the product:

• first there is the time spent inspecting every single piece produced
• then there is the time and other resources spent on rework
• finally there is the costs of scrapping pieces that cannot be reworked

Add to these the extra costs, such as late shipment penalties, or even loss of business due to customer dissatisfaction, and you will see that this approach is an expensive one.