Decision Requirements Graph or DRG in Studio

For the design guide on how to model logic see Decision Management guide.

Table of contents

This information is written to explain how the Decision Requirements Graph (DRG) is integrated in Blueriq studio. The first part is the explanation on how a DRG is used in the studio environment and the second part is a small introduction in Decision Modeling and Notation (DMN).

Decision Requirements Graph in Blueriq studio

In Blueriq studio it is possible to open a DRG for an attribute. It will show a decision model following the path of attributes, it potentially can follow to derive the result for the requested attribute. The DRG will assist a business engineer in understanding how a decision is derived and to get insight in the structure of the decision. 

Blueriq Decision Requirements Graph (DRG) to decide on granting a loan.

In this example model all possible shapes of a DRG are present. Some fragments are verbalized as follows:

• The decision Strategy uses the decision table Strategy table to derive its result.
• The decision Strategy uses the results from the sub decisions Eligibility and Bureau call type as input for its decision.
• In the specification Loan strategy you can find the (legal) source or justification for the decision Strategy.
• The decision Eligibility uses the decision table EligibilityRules to derive its result.
• The decision Eligibility uses the attribute ApplicantData.Age as input.

Opening a Decision Requirements Graph

A DRG can be opened using one of the options listed below:

• Click the icon in the attribute screen (located beside the unit test icon).
• Click the  icon in the drop down when right clicking on an attribute.
• Click the icon in a logic element.
• Use the Alt + G shortcut.

Shapes in a Decision Requirements Graph

Name	Shape	Description
Decision		All attributes that are used in the inference path to set a value for the main decision are displayed as a decision. The name of the decision is the functional name when available. Otherwise the (technical) name is used.
Business knowledge model		A reference to the logic, that will be used to answer the question for the decision. The name of the business knowledge model is the functional name of the used logic element, when not available the (technical) name is used. A default expression gets the name: Default A default constant gets the name: Constant
Input data		The input data displays a list of attributes that can not be derived (user inputs) and that can be used by the knowledge element to set derive a value for the decision.
Knowledge source		The knowledge source will contain a reference to all specifications that are connected to a logic element.

Viewing a Decision Requirements Graph

Opening and closing the Business knowledge model, input data and knowledge source

When opening a DRG, by default the extra shapes for the decision on top will be opened. For the other decisions it is possible to open this extra information as well. When hoovering over a decision, icons will appear at the left side of the decision. Clicking on the icon with the business knowledge model shape will open the extra information for that decision. Clicking the same icon will close the extra shapes when opened.

Opening extra levels

When opening a DRG, three levels of decisions will be displayed. In many situations more levels are available so it must be possible to open these. Two methods are available to open extra levels, using the drop down or open extra levels per path.

Using the drop down

At the upper left corner of the DRG a drop down is available that makes it possible to select the number of levels that should be displayed.

Extending levels per path

When a decision in the lowest level has sub decisions it is possible to open that path separately. When hoovering over the decision shape a + icon will appear. Clicking the icon will open the underlying sub decision(s)

Collapsing all sub decisions

When a better overview is needed collapsing sub decisions or complete paths can be useful. When hoovering over a shape with one or more sub decisions a - icon will appear. Clicking the icon will close all underlying decisions with their sub decisions.

Opening a sub decision as main decision

To get a better overview it is possible to open a new DRG for a sub decision. When clicking the icon a new tab will be opened with the sub decision as the main decision.

Opening the referenced elements

It is possible to open the referenced elements by using Ctrl-Click. For instance when using Crtl-Click at a decision the referenced attribute will open.