An AI (artificial intelligence) program that uses a knowledge base of human expertise for problem solving. Expert systems were the AI methodology prior to the neural networks of today, which are much more powerful.
Relying heavily on the knowledge of human experts, expert systems have been used in medical diagnosis, equipment repair, financial analysis, insurance planning, vehicle routing and production control. Like regular business applications, they use if-then-else logic to make decisions, differing greatly from the more automatic decision making of today's AI systems. See neural network
and deep learning
Inference Engines Do the Work
The inference engine program matches the user's input against its knowledge base and generates a result. In practice, expert systems perform both below and above that of a human. See AI