Abstract
When a designer finds or encounters a problem during a product design and development process, an effective way of ensuring the security and safety of the product is to identify all the possible causes of the problem by FTA and fix them. Although FTA is an effective method, it is not easy for a designer to construct a complete fault tree without any misunderstanding or oversight. A promising approach for supporting FTA is to utilize a computerized knowledge management method. Although many knowledge management techniques for literal expression have been developed, they are not necessarily suitable for managing the engineering design knowledge of physical phenomena. To solve this problem, the authors propose a new design knowledge management approach called quantity dimension indexing and computerized support for FTA such as the verification of consistency of a fault tree.