Expert Systems Expert systems are based on Artificial intelligenceArtificial Intelligence (AI) is an area of computer science whose goal is to develop computers that can think, see, hear, talk and feel like human beings.AI projects develop Industrial Robots and Intelligent computer software.

One of the practical applications of AI is the development of Expert Systems (ES).

An Expert System (ES) is an knowledge-based information system(KBIS), which uses its knowledge about a specific area to act as an expert consultant to users.

ES provide answers to questions in a very specific problem solving area by making human like inferences.

They must be able to explain their reasoning process and conclusions to a user.

ES can provide decision support to end users in the form of advice from an expert consultant in a specific problem area.

ES can support either operations or management activities. In artificial intelligence, an expert system is a computer

system that emulates the decision-making ability of a human expert. 

Expert systems are designed to solve complex problems by reasoning about knowledge, like an expert, and not by following the procedure of a developer.

Components of Expert Systems The components of expert system include a knowledge

Base and software modules that perform inferences on the knowledge and communicate answers to a user’s questions.

Expert Advice

Workstation

User Interfac

e Progra

ms

Inference

Engine Progra

m

Knowledge Base

Expert System Software

The Expert System

Knowledge

Engineering

Workstation

Knowledge Acquisition Program

Expert System Development

Expert and/or Knowledge Engineer

Explanation Program

Query

Advice

Non expert user

Knowledge Base

It containsFacts about a specific subject area

(ex. John is an analyst)Heuristics that express the

reasoning procedures of an expert on the subject (ex. If john is an analyst then he needs a workstation)

Software Modules An ES software package contains an inference engine and

other programs for refining knowledge and communicating with users.

The software modules perform inferences on a knowledge base built by an expert/or knowledge engineer. This provide expert answers on an end user’s questions in an interactive process.

The inference engine program - processes the knowledge (such as rules and facts) related to a specific problem.

User interface programs – used for communicating with end users. It also includes an explanation program to explain the reasoning process to a user if required.

Knowledge acquisition programs – they are not part of the ES but are software tools for knowledge base development.

Expert system shell – is a development tool for developing expert systems.

Advantages Provides consistent answers for repetitive decisions, processes and tasks

Holds and maintains significant levels of information

Encourages organizations to clarify the logic of their decision-making.

Never "forgets" to ask a question, as a human might

Disadvantages Lacks common sense needed in some decision making Cannot make creative responses as human expert would in

unusual circumstances Domain experts not always able to explain their logic and

reasoning Errors may occur in the knowledge base, and lead to wrong

decisions Cannot adapt to changing environments, unless knowledge

base is changed

Application of ES Expert systems are mainly used medicine, engineering,

business etc. For example ES can diagnose illness, search minerals,

recommend repairs and do financial planning. The ES systems asks questions of the user, searches its

knowledge base for facts and rules or other knowledge, explains its reasoning process when asked, and gives expert advice to the user in the subject area being explored.

Inferences The act or process of deriving logical

conclusions from premises known or assumed to be true.

The act of reasoning from factual knowledge or evidence.

Heuristic ( "find" or "discover") refers to experience-based techniques for problem solving

Generally speaking, a heuristic is a "rule of thumb," or a good guide to follow when making decisions. In computer science, a heuristic has a similar meaning, but refers specifically to algorithms.

IE program processes the knowledge(rules and facs) related to a specific problem.