“…To overcome this issue, Tone (2001) proposed slack-based measure model (SBM) whose objective function is unit invariant and its value ranged from zero to one. Since then, several efficiency studies in bank sector have been conducted based on the Tone's (2001) model (e.g., Drake & Hall, 2003;Sufian & Kamarudin, 2014;Zhao & Kang, 2015;Yin, Yu, & Huang, 2018;Zha, Liang, Wu, & Bian, 2016;Wang, Hang, Sun, & Zhao;Wang, Huang, Wu, & Liu, 2014).…”