You can create a new Workflow rule on Project items for this. I suppose your field API name is $C_BriefStatus.
Set a name, set Run Time to "Every time a record is created or edited"
Set Evaluation criteria to "Run only when the following conditions are met" with value = "IsChanged($C_BriefStatus)"
Action 1: New item
Run On: Current Object
$Container = CurrentObject()
$Body = GetPreviousValue($C_BriefStatus)
I hope this helps,