Effective Project Management with MS Project : Resource overallocations

Another potential area where errors can creep into project schedules impacting the delivery of a project is that of overallocation of resources. An overallocation is where a resource is assigned more work than they have capacity to complete it. For example, a resource works an eight hour day and is assigned two tasks, each of eight hours effort, both scheduled to occur on the same day as shown below.


As the resource cannot complete both tasks at the same time, a resource over allocation will occur.

When over allocation of resources occurs in the project schedule, whilst the project effort will remain the same, as the resources completes Task 1 and moves on to Task 2 the next day, the duration of the project will increase by a day.

Both Microsoft Project 2007 and Microsoft Project 2010 make it very simple to identify when there is a resource overallocation.

Project 2007 Project 2010
On the Resource Sheet view, the resource will be coloured red.


On the Resource Sheet view, the resource will be coloured red.


On the Gantt chart view, the task will have a red person indicator next to it.


There are a couple of ways that a resource overallocation can be corrected, how you approach it will depend on which version of MS Project you are using and which method you are most comfortable with.

Manual correction

The simplest method is to manually correct the overallocation. This is most easily achieved by setting a filter on the Gantt chart against the overallocated resource and identifying where tasks are occurring on the same day. Once identified, the tasks can be moved manually by changing the start date, moving the Gantt chart item with the mouse, or moving the hours in the resource usage sheet.

Team Planner

Project 2010 includes a new feature that can assist in resolving overallocations called the Team Planner. Only available in Project Professional 2010, this feature is designed to provide a simple interface to assign resources to tasks, schedule those tasks, and identify and correct resource oveallocations. To invoke the team planner, select the Team Planner view from the view menu.

The default team planner view consists of four quadrants containing:

· Resourced / Unscheduled tasks

· Resourced / Scheduled tasks

· Unassigned / Unscheduled tasks

· Unassigned / Scheduled tasks


To correct overallocations, we are only interested in the Resourced / Scheduled quadrant. As you can see from the above screen shot, tasks 1 and 2 are currently overallocated, as seen by the red highlighting. To correct the overallocation you can either right click on the resource name and choose Level Resource, or my preferred method, drag and drop Task 2 to the next day to remove the overallocation.


Both Microsoft Project 2007 and 2010 include a leveling feature that enables the project schedule resourcing to be leveled either automatically or manually. Whilst present in Project 2007, it was buried in the menus and not easy to find, whereas Project 2010 has surfaced more of the capability.

Project 2007
Select Tools > Level Resources…


Project 2010
Select the Resource tab and Level grouping.


The levelling feature has a variety of options that the user can select when levelling, including the calculation type, the order in which levelling should occur (either based on task id, task priority or standard which is based on a combination of predecessors, slack, dates, priorities and constraints).


I am not going to go into the nitty gritty of levelling as I would be here for hours, but if you want to know more specifics on the leveling feature, check out the online help for a detailed overview of each option.

To level the plan, select Manual calculation, this retains an element of control of the leveling, as opposed to automatically leveling the whole plan. Choose to look for overallocations on a Day by Day basis, leaving the remaining options as is, and click on Level Now to level the plan.

A word of warning though, automated resource leveling function is very powerful, and as we all know, with great power comes great responsibility. It is incredibly dangerous to use the automated leveling features blindly, accepting that Level Now will create a perfectly allocated schedule without going through and checking the minute detail of what the function has done. Certainly experience gained from watching colleagues pulling their hair out after auto leveling the entire plan has turned me off using the feature on more complicated plans.

5 thoughts on “Effective Project Management with MS Project : Resource overallocations

  1. Pingback: Effective Project Management with MS Project « EPMSource

  2. Pingback: Effective Project Management with MS Project – Estimation « EPMSource

  3. Dear All,

    i’m using MS Project 2003, after updete the progress, i started for viewing the zig-zag line with the Progress Line. Normally if the task already finish (100%), the Progress Line will not going zig-zag (straight), but i found some task in my schedule even the task already finish the Progress line still zig-zag. i appreciate if sombody can explain why this one happen…

    thanks all…

    • Hi,

      This might be better asked in the Project forums or newsgroups as my knowledge of Progress lines is pretty rusty (I haven’t used them in years!) But I did a quick search and found that Progress lines use the following rule:

      Progress lines are drawn across the Gantt bar based on a task’s cumulative percentage of completion up to the date you specify. To ensure that peaks are drawn correctly, or to show work that is ahead of schedule, changes to the total percent complete should spread to the status date. On the Tools menu, click Options, click the Calculation tab, and then under Calculation options for, select the Edits to total task % complete will be spread to the status date check box.

      This might be what is causing the problem. You can find more at http://office.microsoft.com/en-us/project/HP452950531033.aspx

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