Design refresh planning models for managing obsolescence

Fast moving technologies cause high-tech components to have shortened life cycles, rendering them quickly obsolete. Obsolescence is a significant problem for systems whose operational and support life is much longer than the procurement lifetimes of their constituent components. Long field-life systems such as aircraft, ships, and other systems require many updates of components and technology over their life to remain in manufacture and supportable. Design refresh planning is a strategic way of managing obsolescence. In this article, efficient mathematical models based on Integer Programming for design refresh planning are developed to determine the plan that minimizes the total obsolescence management costs. Decisions are made on when to execute design refreshes (dates) and what obsolete/non-obsolete system components should be replaced at a specific design refresh. Data uncertainty is also considered and obsolescence dates of the components are assumed to follow specific probability distributions. With this approach, different scenarios of executing design refreshes and the probabilities of adopting these scenarios can be determined. The final optimal cost becomes an expected value. An example of an electronic engine control unit is included for demonstration of the developed models.