guest post by Ryan Trollip, Practice Director, Decision Management – www.prolifics.com
‘Expert system’ covers a pretty broad swath. Rules engines in the business world, in practicality, and in the majority of implementations, are simply operationalizing decisions, whether derived by predictive modeling or prescriptive business rules (e.g., regulatory). The conditions that reach a decision are largely pre-determined and operationalized in the rules system.
Yes, there is a RETE algorithm involved. But don’t be fooled, this doesn’t give it intelligence, it is simply a style of execution. You can argue that in some implementations, sequential (non-forward chaining) is sufficient.
In the real world, the management tools for rules systems, in my opinion, are more important than the algorithm. They have become the focus to externalize rules and allow for rapid change.
I wouldn’t call a business rules system an expert system although you could probably create one with the tools out there. It’s simply a specialization much like how DBMS came about to better handle data. Not as sexy as AI, imperfect reasoning, etc., but certainly useful and practical.