International Journal of Computing & Business Research ISSN (Online): 2229-6166 Proceedings of ‘I-Society 2012’ at GKU, Talwandi Sabo Bathinda (Punjab) Research Aspects of Expert System Yogesh Kumar 1 , Yogyata Jain 2 Student M.Tech 1 , Assistant Professor CSE Department 2 Guru Nanak Dev Engg. College, Ludhiana 1 , IET Bhaddal Ropar 2 Kumar_yogesh1087@rediffmail.com 1 , yogyatagupta2010@gmail.com 2 Abstract An expert system is a computer program that simulates the judgment and behavior of a human or an organization that has expert knowledge and experience in a particular field. It is a program that emulates the interaction a user might have with a human expert to solve a problem. The end user provides input by selecting one or more answers from a list or by entering data. An Expert System is a problem solving and decision making system based on knowledge of its task and logical rules or procedures for using knowledge. Both the knowledge and the logic are obtained from the experience of a specialist in the area. This paper introduces introduction, structure, new tools and applications of expert system. In this paper advantages and limitations of expert system and the various research approaches in expert systems are discussed. This paper also outlined current research trends which are going on expert system and why the various Industries are planning to use expert system. 1. Introduction An Artificial Intelligence System created to solve problems in a particular domain is called an Expert System. An expert system is a computer program that simulates the judgment and behavior of a human or an organization that has expert knowledge and experience in a particular field. An expert system may be viewed as a computer simulation of a human expert. Expert systems are an emerging technology with many areas for potential applications. Past applications range from MYCIN, used in the medical field to diagnose infectious blood diseases, to XCON, used to configure computer systems. Expert systems are typically very domain specific. For example, a diagnostic expert system for troubleshooting computers must actually perform all the necessary data manipulation as a human expert would. The developer of such a system must limit his or her scope of the system to just what is needed to solve the target problem. Special tools or programming languages are often needed to accomplish the specific objectives of the system. 2. Expert System Structure Complex decisions involve intricate combination of factual and heuristic knowledge. In order for the computer to be able to retrieve and effectively use heuristic knowledge, the knowledge must be organized in an easily accessible format that distinguishes among data, knowledge, and control structures. For this reason, expert systems are organized in three distinct levels: