All products have certain inherent weaknesses dictated by the product and it's intended use. Automobiles manufactured for use in the northern climates must be resistant to road salt. House paint must be resistant to sunlight, heat, cold, and humidity. In each of these examples, the manufacturer of the product is well aware of the threats to prolonged product lifetime. Having this information, manufacturers seeking to provide a high level of product reliability and product life will make every effort to minimize the effects which the threat will have over the expected product life.