Reviewing Interference for All Modes of Products for Failure Avoidance

Industrial products today often go through reuse or recycle for extended times and sometimes are even taken through different environments. Our product development needs to be more sustainable than ever to meet such needs. Insufficient sustainability often leads to exposing interferences that the designer overlooked and causes accidents like the three cases we discuss in this paper. Axiomatic design is a tool to aid the designer in identifying design interferences during the early design stage so the designer can remove them and create higher values through sustained use of the product. One of the three failures we discuss is a new safety feature of locking the handle shaft of a parked bicycle that accidentally kicked in while riding. The design posed a threat to the sustainability of society. The second, an automated train that started in the wrong direction and collided with the bumping post, causing societal and economic damages. The third is about conflicting functions of a part that the designers overlooked in the Fukushima Nuclear Power Plant-1, Unit-1. This disaster was and still is a threat to the social, economic, and environmental sustainability. Despite no direct fatalities, these accidents all caused serious injuries, and in the case of Fukushima, many indirect deaths. Squeezing out flaws from our designs is important in protecting people, the economy, and the environment now and for our future for sustainability. The designer should carry out failure analysis for all parts of a product in all modes of operation.