Paper Title
A Review on The Expert System Practices

Abstract
The objective of this paper is to illustrate the importance of expert system is to transfer knowledge from experts and their experience to a computer-based system so as to arrive to the same conclusion of the human experts. Expert systems are adopted when users need recommendations or suggestions for the specific domain by collecting and gathering expertise from different but valuable sources. Solving problems is the same way as human experts do, is a great advantage of expert systems over conventional computer applications. Expert systems give users the ability to solve a wide range of problems in a specific domain that classical or traditional methods cannot. Expert systems have popular in different sector and their applications are widely used. Some useful applications of expert systems in various fields include: production planning systems, advisory systems, teaching advisory systems, automobile process planning, system development, medical treatment, automobile repairing system, management advisory system, communication systems, material processing design, agriculture planning system, sensor control, tutoring system, urban design, financial advisory system, and plant process control. Typically, expert system consists of four major components. The Knowledge base is the first, main and most important component of an expert system. The knowledge of domains (which is obtained from the experts and valuable documents) and their facts are stored in the knowledge base. The inference engine is the second component. The role of inference engine is to search the knowledge base by means of reasoning on facts and rules in order to find the answers to questions asked by the users. The duty of the working memory is to contain the data which are entered into the system by user sand hold them in memory. The last component is the user interface, which is the interactive layer between an expert system and users and acts as a communication tool in order to receive input and output. Index Terms - Artificial Intelligence, Expert system, Fuzzy logic, Traffic accident.