I believe your post actually involves two different questions. You originally talked about project risks but then asked for an example of a product risk. Product risks refer to potential defects within the product itself. This could be something like designing a software that will need to continue to be updated after the product is initially launched. Project risks affect the schedule of developing a product. This is something that can be limited during the initial planning phase and can be directly addressed by using a spread sheet to list and manage all risks.