Table of Contents
What is Expert System? Or Knowledge Base System
- It is a system that allows a person not having any specialized knowledge or experience to make a decision.
- Expert system is a computer based information system which provides the advices or solution of problems just like human experts.
- Expert system works on the principle of Artificial Intelligence to solve complex and unstructured problems normally in a narrow problem area like audit etc just like human experts.
- Expert systems are also known as Knowledge Based Systems, because these systems contain the knowledge of experts in organized and structured manners to solve the problems.
A knowledge base, which is typically a combination of accumulated experience and an inference/rules engine — a set or rules that allow the expert system to apply the knowledgebase to any particular situation that is described by the program — makes up an expert system. The system’s capability can be increased by adding to the knowledge or to the existing set of rules. Current systems may include machine learning capabilities that allow them to improve their performance based on experience, just as humans do.
Expert systems are used in many industries, such as financial services and telecommunications. They also play an important role in healthcare, customer support, transport, video games, manufacturing, aviation, and written communications. Dendral, a system that helped chemists identify organic compounds, and MYCIN (which helped to diagnose bacteria like bacteremia or meningitis and recommended antibiotics and dosages), were two of the pioneering expert systems in the healthcare sector.
Components of Expert System
- User Interface allows a user to provide, design or communicate the problem to expert system for solution
- Inference engine is most important component of expert system.
- It is like a search engine on internet.
- It contains various rules and logics to arrive at solution for problem provided by users by matching the problem solution from knowledge base.
- It is like a reporting system, it provide an explanation of logics to users for solution arrived by expert system.
- Knowledge base contains the past knowledge of experts for problem solutions in an organized manner
Knowledge Acquisition Facility:
- This component is used for building knowledge base of an expert system.
- This component is used by knowledge engineers for knowledge and expertise of human expert to enter the knowledge and expertise in knowledge base.
Characteristics of Expert System
• Expert System provides problem solution or provides advice like human experts.
• Expert System can be
- Rule Based
- Example based
- Frame Based
- In Example Based Expert System it searches the appropriate match for present problem orcase with previous cases and their solutions from knowledge base.
- In Rule Base Expert System it uses if then else rules for serried of questions from users to draw conclusion for problem solution.
- In Frame Base Expert System it divide every data, processes etc into logically linked units called frames to create the most logical solution.
The Expert System provide various level of expertiese like:-
- Assistant Level: provides user attention on problems.
- Colleague Level: in this case user discusses the problem with the system until both agree on a solution.
- True Expert: User accepts the solution without any questions. It is quite difficult to develop this type of system.
Advantages and disadvantages of Expert system
Adavantages of Expert Systems
- Provide low cost solution or advice
- They increase productivity and preserve the expertise of an expert, if he leaves the organization
- Provide solution or advice based on the knowledge of many experts.
- Always available for solution and advice, there is no time restriction etc as it happen in the case of human experts
- Help user in better decision making and also improve their productivity
Disadavtages of Experts system
- Development is costly and time consuming.
- It is difficult to accumulate knowledge from experts as it is difficult for them to specify they make a decision.Common sense of user cannot be programmed. When a situation that has not been not programmed arises, the rule based system breaks down.