Techniques from decision analysis and expert system have both been extensively used in the development of computerized decision aids, although each discipline uses different approaches in knowledge (information or input) acquisition, representation, and problem solving methodology. From the perspective of many types of practical decision aiding applications, both normative decision aids and expert system technology have significant limitations. Many research efforts have been exerted toward complementing the ones deficiency with the others possible techniques or vice versa. In this paper, among many possible complementary techniques for better decision aiding between decision analysis and expert system, we focus on the using prescriptive methodology of decision analysis which incorporates users preference knowledge for conflict resolution in rule based expert system.