What are the advantages and disadvantages of expert system?

* * * * * * \ * 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 Can work round the clock Can be used by the user more frequently ** A multi-user expert system can serve more users at a time 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