The damages from DDoS attacks are increasing as DDoS attacks are taking various forms. This has resulted not only in decreased reliability of organizations and corporations but also in the threat of national security. Organizations and corporations are making significant efforts in developing a system through which they can appropriately correspond to DDoS attacks. However, the studies on objective index for evaluating the performance of DDoS correspondence are lacking. The majority of the existing studies have been on the information protection & management system on a large scale. Accordingly, the scope of this thesis will be limited to DDoS correspondence to propose correspondence index for quantitatively measuring and managing them. The statistical techniques such as SMART technique and factor analysis will be utilized accordingly.