Why Java code is bad for rules and a declarative alternative

One of the selling features of Drools, and one of the reasons we are often chosen over competitors, has always been the ability to allow the use of Java code in specific parts of rules; expressions and consequences. This makes for a lower learning curve as Java developers can start writing consequences without additional training;Read more →

Real World Rule Engines

Here is an excellent article, introduction reproduced below, from our very own mailing list mentor Geoffrey Wiseman:http://www.infoq.com/articles/Rule-Engines For many developers, rule engines are buzzwords, or black boxes on an architectural diagram: something to be feared or admired from afar, but not understood. Coming to terms with this, is one of the catch-22s of technology: It’sRead more →

Rule Execution Flow with a Production Rule System

Some times workflow is nothing but a decision tree, a series of questions with yes/no answers to determine a final answer. This can be modelled far better with a Production Rule System, and is already on the Drools road map. For the other situations we can use a specialised implementation of Agenda Groups to modelRead more →

What is a Rule Engine

Drools is a Rule Engine but it is more correctly classified as a Production Rule System. The term “Production Rule” originates from formal grammer – where it is described as “an abstract structure that describes a formal language precisely, i.e., a set of rules that mathematically delineates a (usually infinite) set of finite-length strings overRead more →