The Peak field indicates the maximum percentage or number of units for which a resource is working at any one time on an assignment.
For example, let's say Joe is assigned at 100% to Task A. As a full-time employee, Joe works an 8-hour day. This means that Joe should be spending 100% of those 8 hours each day on Task A. That 100% is Joe's Assignment Units value. On the Friday when Joe is supposed to have Task A done, he spends an extra couple of hours on it, trying to wrap things up. He worked 8-hour days on Monday through Thursday (100% of his time each day), but on Friday he worked a 10-hour day (125% of the amount of time he was supposed to work). The Peak field will reflect that 125%.
Peak is a helpful value to review when looking at resource requirements for your project, and even across your organization. If you have a resource that is consistently showing Peak values that are higher than his or her Assignment Units values, it's worth looking at what that resource is bringing to the project. You may need to assign more people to help, or replace the resource with someone who is better suited for the work.
Note: Isn't Peak also reflected in the Assignment Units field? The quick answer here is no! In versions prior to Project 2010, the Assignment Units field was used to capture how much of a resource's time was allocated to the project's tasks. It was also updated as the project progressed, to reflect the maximum amount that a resource was working on a task at any one time. This created scheduling issues, so the Assignment Units field was tuned to maintain its value even as actual work was added to the project. The Peak field captures the maximum units value for an assignment, and can be used to identify overallocation amounts.
Data Type Percentage/Number
Entry Type Null field
Best Uses Add the Peak task field to the table portion of the Task Usage view when you want to see the corresponding Peak fields for the individual assignments on the task.
Example You are reviewing the peak resource allocations for task assignments. You add the Peak field to the Task Usage view. No information appears in the Peak field next to the task name itself. However, the peak values for the tasks' assignments appear in the Peak assignment fields below each task name. You see that for the "Coordinate trade show" task, Jamie has a peak allocation of 125 percent and Chris has a peak allocation of 50 percent.
Remarks Although you can add the Peak field to a task sheet such as the Gantt Chart, no data appears in the field. It's a null field, provided to give context to the Peak assignment field in the Task Usage view.