“…In addition, it is a tool suitable for analyzing quantitative and qualitative attributes. RST has been successfully applied in many different fields, such as controlling industrial processes [9,29], diagnosis analysis [42,51], image processing [43], market decision-making [1,16,49], environmental problem detection [11,39], knowledge acquisition [17,56,57], web and text categorization [12,18,30] and early warning [7,55]. Unfortunately, it is rarely applied to the prediction problem of credit rating [10].…”