Product designers create objects meant for use by the public or businesses, such as phones, cars and cookware. Reliability testing is also useful for testing software to make sure it isn't prone to crashes. Of course, there are thousands of different gadgets in the category of product design. Although the way a product looks is meaningful, even more critical is how functional that item is. If you create a product and it doesn't fulfill its promises, you'll have a lot of unhappy customers.