Enterprise Architect provides the Decision Tables facility, based on the OMG Decision Model and Notation (DMN) specification (2014). As stated in this document:
"The purpose of DMN is to provide the constructs that are needed to model decisions, so that organizational decision-making can be readily depicted in diagrams, accurately defined by business analysts, and (optionally) automated. ...
... DMN provides a common notation that is readily understandable by all business users, from the business analysts needing to create initial decision requirements and ... more detailed decision models, to the technical developers responsible for automating the decisions in processes, and ... the business people who will manage and monitor those decisions. DMN creates a standardized bridge for the gap between the business decision design and decision implementation."
DMN is designed to be usable beside BPMN, and to support the exchange of decision models across organizations via XML.
The Decision Tables facility provides a simple method of modeling how a decision is made, and provides the capability of generating code for the decisions.
This example illustrates how you could model a decision on an insurance Risk Rating based on the applicant's age and medical history.
On the diagram containing the Activity or Action element that owns the table, you can replace the element shape with the decision table itself, showing the rules as either columns or rows. You specify the table format, or whether to redisplay the element shape, using options on the element context menu.
Design > Element > Decisions
On a diagram:
Right-click on Activity element | Decision Table or
Right-click on Action element | Decision Table