Abstract
Traditional engineering has focused its attention and efforts on achieving excellent functions of a final product. Engineers thought the better functions are, the more they would satisfy their customers. But with the increasing diversification, customers would like to have products that will break in better to their use conditions so that they can enjoy using the machines and products. In other words, we have to develop a new way to customize our products. In order to achieve this goal, we have to develop a new way to control degradation so that the machines and products degrade in such a way that we can enjoy using them as much as we like. The new technology of digital material might help to achieve this goal and modular design which separates parts into functional ones and emotional ones is expected to be very effective for this purpose.
