Chapter 1. Welcome

I've always stated that end business users struggle understanding the differences between rules and processes, and more recently rules and event processing. For them they have this problem in their mind and they just want to model it using some software. The traditional way of using two vendor offerings forces the business user to work with a process oriented or rules oriented approach which just gets in the way, often with great confusion over which tool they should be using to model which bit.

PegaSystems and Microsoft have done a great job of showing that the two can be combined and a behavioural modelling approach can be used. This allows the business user to work more naturally where the full range of approaches is available to them, without the tools getting in the way. From being process oriented to rule oriented or shades of grey in the middle - whatever suites the problem being modelled at that time.

Drools 5.0 takes this one step further by not only adding workflow with Drools Flow but also adding event processing with Drools Fusion, creating a more holistic approach to software development. Where the term holistic is used for emphasizing the importance of the whole and the interdependence of its parts. Drools 5.0 is the launch of what we call the Business Logic integration Platform (BLiP) .

Drools 5.0 is now split into 4 modules, each with their own manual - Guvnor, Expert, Fusion and Flow. Guvnor is our web based governance system, traditionally referred to in the rules world as a BRMS. We decided to move away from the BRMS term to a play on governance as it's not rules specific. Expert is the traditional rules engine. Fusion is the event processing side, it's a play on data/sensor fusion terminology. Finally there is Flow which is our workflow module.