Enumeration types not available to be required properties

Yes, Attributes of type enumeration is not seen in required properties list. It can be included by editing the Process configuration source file in project area.
Search for
operation id="com.ibm.team.workitem.operation.workItemSave"
Where Preconditions are listed.
Say if you want to make attribute as required for work item type story, then go to the properties section where workitem type story is there.
Add the following line in properties section
<property>
save the project area.
If you create workitem type story, then the above attribute is seen as required field. Hope this helps you.

Enumeration attributes, as they are treated by now, always have a valid value (initially the default value). This is the reason why enumeration attributes do not appear in the required properties section of the operation behavior editor.

Regards

Marcel
Jazz Work Item team