抄録
This paper proposed a new method of robust design using fuzzy number operation and entertains the effectiveness through comparing a traditional method of robust design. We solve minimization of the weight of spring using that new method of robust design using fuzzy number operation. Later, we entertain the effectiveness through comparing results using traditional method of robust design. Additionally, we entertain what influence the result receives by adding a new constraint. As a result, it is proven to be able to find the best design that the designer requests.