As the rule base is in everyday language (the engine is untouchable), expert system can be written much faster than a conventional program, by users or experts, bypassing professional developers and avoiding the need to explain the subject.
Expert System: Meaning An expert system is a computer system that competes with the decision-making ability of a human expert. Designed to solve complex problems by reasoning about knowledge, like an expert, and not by following the procedure of a developer as is the case in conventional programming.
Meaning Continued It is a computer program that represents and reasons with knowledge of some specialist subject with a view to solving problems or giving advice It is divided into two parts. Fixed, independent of the expert system: the inference engine. Variable: the knowledge base. Conversational: A dialog interface to communicate with users.
Software architecture The rule base or knowledge base In expert system technology, the knowledge base is expressed with natural language rules IF ... THEN ... For examples :"IF it is living THEN it is mortal" "IF his age = known THEN his year of birth = date of today - his age in years.
The inference engine The inference engine is a computer program designed to produce a reasoning on rules. In order to produce a reasoning, it is based on logic. With logic, the engine is able to generate new information from the knowledge contained in the rule base and data to be processed.
Advantages Evolving an expert system is to add, modify or delete rules. Since the rules are written in plain language, it is easy to identify those to be removed or modified. Quick availability and opportunity to program itself. The reliability of an expert system is the same as the reliability of a database, i.e. good, higher than that of a classical program.
Disadvantages Knowledge collection and interpretation into rules, the knowledge engineering. Expert knowledge is not well understood: there is a lack of rules, rules are contradictory, and some are poorly written and unusable. Expert systems most often use an engine incapable of reasoning. Therefore, oftentimes the expert system works poorly and the project is abandoned
Application field Highly interactive or conversational applications, IVR, voice server. Fault diagnosis, medical diagnosis Decision support in complex systems, process control, interactive user guide. Educational and tutorial software. Logic simulation of machines or systems Knowledge management. Constantly changing software.
Thank You IF= Nerds are bad, THEN = Politicians are… error !