Assign a Work Item
You assign a Work Item to a person using the Assignee field in the Work Item detail. This field presents a drop-down list of Polarion users (filtered according to permissions). You assign the selected Work Item (or Items, if performing a Bulk Edit) by selecting the user's name from the list. Note that the assignee must have an account on your Polarion system, and must be assigned the assignable role in order to appear in the Assignee list. (It can be easy to omit setting up accounts, or assigning roles for e.g. a domain expert who is not on the engineering team but who needs to be assigned a Requirement, for example.) For more information on roles, see: Configure User Roles.
Assign to multiple assignees
It is possible to assign the same Work Item to multiple people. For example, you might have a Work Item type "Meeting" which is scheduled, and for which you want to track time spent by all participants. You can accomplish this by assigning the item to multiple assignees.
The procedure is essentially the same as for assigning a single person. After you assign the first assignee, click 
in the Assignee field, and select another user name from the drop-down list.
When there are multiple assignees, each additional assignee has a 
icon beside the user name. If you need to remove an assignee, click this icon. The Assignee field cannot be left empty. To unassign the item completely, select the not selected value in the drop-down list of users in the Assignee field.
Any of the assignees who spend time on a Work Item with multiple assignees can create a Work Record to report time spent on it.