• The heart of the Rules Engine where you specify conditions (if ‘a’ then ‘b’).

learn drools tutorial - drools project - how a rule based engine works - drools example programs

• Facts are the data on which the rules will act upon. From Java view, Facts are the POJO (Plain Old Java Object).

learn drools tutorial - drools project - when to use rule engine - drools example programs

• A Data Session in Drools is the core component to fire the rules. It is the knowledge session that holds all the rules and other properties. A Knowledge Session is created from the Knowledge Base. For the rules engine to work, Facts are inserted into the session and when a condition is met, the subsequent rule gets fired. A Session is of two types:
• Stateless Knowledge Session
• Stateful Knowledge Session


learn drools tutorial - drools project - how a rule based engine works - drools example programs

• It’s a rational concept. The program is the logical place where activations are waiting to be fired.

• Activations are the then part of the rule. Activations are placed in the agenda where the dsssuitable rule is fired.

learn drools tutorial - drools project - imperative vs declarative rule statements - drools example programs

learn drools tutorial - drools project - drools fusion - drools example programs

learn drools tutorial - drools project - drools fusion workflow management - drools example programs

learn drools tutorial - drools project - drools flow - drools example programs

learn drools tutorial - drools project - drools guvnor - drools example programs

learn drools tutorial - drools project - drools planner - drools example programs

drools planner workflow