New work item
Using this button, you can enter -during a measurement- a new
group of work items or a new work item that does not exist in the WBS, and link
it to the result of the measurement. If you click the 'Add work item' button,
the 'WBS' window will appear on your screen. Add the desired group/work item
(See General/WBS (Ctrl+Β) XE "WBS" 
) and click 'Close'.
The changes will appear in the 'Select Work Item' window as well as in the 'WBS'
tab (See Work
items).
Apart from adding a group/work item,
you can also edit the description or any other detail of the existing
groups/work items in the WBS or even delete some of them.