https://blog.gongquiz.com/2021/01/18/%eb%8b%a4%ec%9d%8c-%ec%a4%91-%ec%9c%84%ed%97%98-%eb%b0%8f-%ec%9a%b4%ec%a0%84%ec%84%b1-%eb%b6%84%ec%84%9dhazop-%ec%88%98%ed%96%89%ec%97%90-%ea%b0%80%ec%9e%a5-%ec%a2%8b%ec%9d%80-%ec%8b%9c%ec%a0%90/