Henry Petroski wrote a wonderful book ‘Success through failure’ on the importance of failures in the design of successful projects, buildings, policies etc. Petroski is a professor in civil engineering and history at Duke university. The book stress the importance of failures in designing successes. Building only on successes might actually lead to severe failures. Petroski discuss designs of various objects like presentations (from the cave to powerpoint), bridges, sky crapers, etc. A lot of these designs are improvements of earlier designs. Due to thinkering with previous designs, previous failures are avoided, but new ones may occur. By being open to learn from failures, robust designed objects may evolve.
An interesting observation is the regularity of major failures in the design of bridges. Every generation of engineers, a major failure occurs. Probably with a new generation, lessons from previous failures get ignored or forgotten, and less emphasis is made on double checking and testing the designs.