A manufacturing defect is when the product left the manufacturer’s control and then the intended results were not achieved. It somehow differed from the manufacturer’s intended results but was marketed as the same type of product. For example, it could be a watch that explodes when it gets a little warm. On the other hand, a design defect is when the product is manufactured exactly as was intended, but there was a legally defective design flaw. There are two different tests to determine whether or not a design is effective. One is a consumer expectation test to see if a product will perform as safely as an ordinary consumer would expect. The next is a risk benefit test where the question is asked if the danger of the product outweighs the benefits.