business rule management system (BRMS)

Fact

Facts are the knowledge of DROOLS. Facts are plain old java objects (POJO) where data for rules are stored.

Working Memory

Facts are placed in working memory which will be used for pattern matching at later stage. A user can retrieve, insert or modify facts. 

Rule

Rules are a piece code which contain business logic's 

Rule Engine

A business rules engine is a software system. Rule engine executes multiple business rules in a production environment. Rule engine have a Inference Engine,production and working memory. Businesses rule are put into  production memory. Facts (Data) is placed in working memory. Inference engine matches facts against each rule in the production memory. Inference Engine uses Linear, Rete, Treat or Leaps algorithm for pattern matching. DROOLS uses extended Rete Algorithm, ReteOO for pattern matching. When many rules becomes true for same fact, it creates conflict. Agenda uses Conflict Resolution strategy to manage the execution. Rule engine architecture is as shown below

Basic Drools Concepts

DROOLS is a business rule management system (BRMS) . It  have a forward chaining inference based rules engine known as a production rule system, using enhanced Rete algorithm. DROOLS run only on Java platform. This article provides an insight into various DROOLS features and its use. Major components of DROOLS are

• Drool Expert (Rule Engine)
• Drool Guvnor (BRMS/BPMS)
• Drool Flow (Workflow)
• Drool Fusion (Reasoning)

Steps to install DROOLS plugin and create DROOLS Project in Eclipse

JBOSS DROOLS is a business rule management system (BRMS). This document explain in detail step by step procedure to setup DROOLS in Eclipse IDE for work flow configuration and rule development. Eclipse IDE version used in this article is Eclipse Java EE IDE for Web Developers, Version: Indigo Service Release 2. 

To start with , we need to install DROOL software in Eclipse. To do that 

Go To  Help →  Install new software . A pop up appears as shown below . In Eclipse 3.4.1, go to Help → Software Updates.