Expert Systems

An expert system, also called a knowledge-based system, is a type of application program used to make decisions or solve problems in a particular field. It uses knowledge and analytical rules defined by human experts in a field. It is called an expert system because it depends primarily on the knowledge of human experts. It functions like an expert in a discipline, solving problems that require knowledge, intelligence, and experience. Expert systems are a key part of many decision support and executive support systems.

The two major components of an expert system are a knowledge base and an inference engine. A knowledge base contains the accumulated body of knowledge of human experts in a particular field. The knowledge is a combination of data and rules to be applied to the data. The knowledge base is the most important component of an expert system. The performance of an expert system is a function of a size and quality of that knowledge base. The inference engine is the software that applies the rules from the knowledge base to the data provided by the user to draw a conclusion.

A number of commercial tools are available to build expert systems, making it unnecessary to create such systems from scratch. These tools are known in the industry as shells, or expert system shells. Most shells contain all of the components of an expert system except the knowledge base. Thus, buyers need to add only a knowledge base to create their own expert systems.

Many businesses have been using knowledge-based systems to provide quicker and easier problem detection as well as assistance in problem solving and decision making, thereby improving productivity and reducing the costs of operation. They are used in offices, hospitals, research laboratories of various types, industrial plants, manufacturing shops, repair shops, oil wells, and the like.