StudyEventGroupDef is a study building block that groups a number of smaller building blocks, which can themselves be StudyEventGroups or StudyEvents. It thus allows nesting of building blocks.

A partial example of a study diagram, and how study cells and study elements are described using StudyEventGroupDef, is provided below.

The WorkflowRef references a workflow definition, a WorkFlowDef.

Worflows that describe the workflow of the complete study will be referenced from the Protocol element. A workflow referenced by a StudyEventGroupDef will then typically represent a workflow within a study cell (when ArmOID and EpochOID are populated), or represent a workflow within a study element or study subelement.