I would say that the quality control function could be both a value and non value add area. Ensuring the quality of a product is important to building consumer trust and loyalty. If a customer has a bad experience because of a low quality product then they may not purchase from you again. In this way I see quality control as a value add area. In terms of manufacturing, quality control does not add anything to the product to make it better. It only ensures that the product meets standards set by the company. Looking at it in this way can make quality control seem like a non value add. I think that the industry and product would be very important in determining this. One example could be Rolex. If different watches produced by Rolex had many quality control issues they would likely hurt their reputation as a premium or luxury good and hurt their business as whole. Seiko on the other hand could likely get away with worse quality control as their watches are viewed as more affordable.