Reducing the Risk of Failure by Deliberate Weaknesses

The deliberate weaknesses are deliberately created weak spots towards which a potential failure is channelled. By channelling failure into weak spots, designed to fail in a predictable way, the consequences from failure are reduced. Should unfavourable conditions occur, the deliberate weakness is the one to fail and protect the expensive parts of the system. The chapter demonstrates that reducing risk by introducing deliberate weaknesses is a powerful domain-independent method which transcends mechanical engineering and works in various unrelated areas of human activity. A classification has been proposed of categories and classes of deliberate weaknesses reducing risk as well as discussion related to the underlying mechanisms of risk reduction. The chapter also demonstrates that in the case where the cost of failure of the separate components in a system varies significantly, an approach based on deliberate weaknesses has a significant advantage to the equal-reliability/equal-strength design approach.