Expert systems are developed with the aim of efficient and maximum utilization of technology in place of human expertise.

User must be able to interact with system easily. To facilitate use interactions, system must process two properties:

ES must be able to explain its reasoning. In many cases user are interested in not only knowing the answers to their queries but also how the system has generated that answer. That will ensure the accuracy of reasoning process that has produced those answers. It is important that the system must store enough meta-knowledge about reasoning process and should be able to explain it in user understandable way.

The system should be able to update its old knowledge by acquiring new knowledge. As knowledge base is where the system's power resides, expert system should be able to maintain the complete, accurate and up to date knowledge about the domain. It must have some mechanism through which the programs will learn its expert behavior from raw data.