I am trying to build a worksheet to help create schedule assignments.
Columns show the date, and the people being assigned are list in Column A. I
have set up data validation, so that people can only be assigned to specific
tasks, found in the list source. However, I want to ensure that only one
person is assigned to any one task in the list. Later, I will also want to
set up a protocol to make sure that someone is in fact asisgned to every task.

Any suggesdtions on the best way to achieve this?

Thanks