How to Resolve Resource Overloads
Take advantage of any slack time that may exist in your assigned activities.
Slack time is the maximum time you can delay an activity without delaying the earliest date by which you can finish the complete project. Consider starting one or more activities earlier or later.
For example, if Activity 3 has at least one week of slack time remaining after its currently planned end date, you can reduce your total work on the project in week 3 to 40 person-hours by delaying both the start and the end of Task 3 by one week.
Assign some of the work you were planning to do in week 3 to someone else currently on your project, to a newly assigned team member, or to an external vendor or contractor. Reassigning 10 person-hours of your work in week 3 removes your overcommitment.