Response to: Business Rules vs. Expert Systems: Same or Different?guest post by Hafedh Mili, Professor of Computer Science at University of Quebec Montreal and Computer Software Consultant I agree that expert systems and business rules tackle different problems. Expert systems tackle two problems:
(1) Difficult problems with no exact solutions – requiring heuristic knowledge.
(2) Scarcity of expertise.Hence, their first applications tackled complex engineering (and medical problems). Business rules tackle different challenges with respect to common business knowledge:
(1) Externalization (explicitation).
(2) Uniformization.(Yes, I did just make up some new words.) There was no algorithmic/procedural INTERNIST that preceded the expert system INTERNIST. In contrast, plenty of business information systems implement business rules today – just not in the proper, agile way. So why did expert systems fail? Actually, did they fail? Was it a technical/scientific problem, or a business (model) problem? One could argue that expert/knowledge-based systems failed to solve the fairly challenging technological-economic problem of building true expert systems in a cost-effective way. What the science has been able to build is idiot-savants – i.e., systems that manipulated symbols and churned out ‘decisions’ without ‘understanding’ what they were manipulating. When INTERNIST is told about an old Chevy that overheats and has brown/reddish spots on its body, it comes up with MEASLES as a diagnosis. To make such systems less brittle, they need common sense. Doug Lenat (instigator of the CYC project) wittingly characterizes such common sense as “the things you need to know that enable you to disbelieve every word you read in ‘the News of the World’ (i.e., tabloids)”. Building such a common-sense knowledge base is not only costly, but epistemologically (and from an engineering point of view) a far more difficult problem than, say, codifying the debt-over-income requirements for applicants seeking multi-borrower mortgage loans. So, business rules vs. expert systems? Same mechanics (rules and rule engines), but significantly different problems. ~~~~~~~~~~~~~~~~~~ My reply: Hafedh, Great response. Not sure about the ‘same mechanics’ though. But that’s a post for another time.