PRJ2000: Error Message: Microsoft Project Cannot Resolve the Overallocation of <Resource Name>

In Microsoft Project 2000, when you attempt to level a resource, you receive the following error message: Resource name is the name of the overallocated resource, and date/time is the date and time when the overallocation period begins.

NOTE: Depending on the type of overallocation, the exact error message that you receive may be different from this message.

This behavior occurs because of the way that Microsoft Project compares and calculates certain values (specifically, values in the 68 to 70 percent range).

Microsoft Project 2000 uses a double-precision data type for Units values. When comparing doubles directly, sometimes Microsoft Project actually compares values that are slightly higher or lower than the values that you enter.

For example, if you enter 70% in a resource's Max Units field and then assign that resource to a task at 70% Units, Microsoft Project may compare these values as 70.000001% Max Units and 70.000002% Units, resulting in an overallocation.

To resolve this problem, obtain Microsoft Project 2000, Service Release 1 (SR-1).

To obtain SR-1, click the article number below to view the article in the Microsoft Knowledge Base:

Temporary Workaround

To temporarily work around this problem, follow these steps:

1. After you assign the resource at its Max Units, manually type the work for the assignment in the Resource Usage View. For example, if a resource is assigned at 70% Units to task A and B, and tasks A and B are one-day tasks, the resource works 5.6 hours on each task.
2. When you look at the Resource Usage View in the Details window, manually type over the work entries for individual tasks with the same value (for example, if the work entry appears as 5.6h, type 5.6h). Microsoft Project recalculates the assignment, and removes the overallocation on individual task assignments.
   
   NOTE: The overallocation still appears on the Summary Task Assignment, but this is expected because the resource is working 11.2 hours on an eight-hour work day.
3. You can now level this resource successfully. On the Tools menu, click Resource Leveling, and then click Level Now.

NOTE: When you use this method, make sure that your timescale is adjusted to show the details of a contour, if applicable. For example, if your timescale view is set to weeks and days, you can only see the total number of hours worked in a particular day. But maybe this assignment is broken down into an hourly contour, with the resource working only 0.2 hours for the first hour of the working day (for example, from 8:00 AM to 9:00 AM) , 0.4 hours for the second hour of the day (for example, from 9:00 AM to 10:00 AM), 0.6 hours for the third hour of the day (for example, from 10:00 AM to 11:00 AM), and so on. In this case, you want to adjust your timescale view to Weeks and Hours and then follow the workaround steps above, which maintains the integrity of your contour (if this is what you want). To adjust the timescale's units, follow these steps:

1. On the Resource Usage View, right-click the gray area to the right of Details, and then click Timescale.
2. Change the Units setting under Major Scale to indicate the units that you want (that is, Days).
3. Change the Units setting under Minor Scale to indicate the units that you want (that is, Hours).

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was corrected in Microsoft Project 2000, Service Release 1 (SR-1).

For additional information about overallocated resources, click the article number below to view the article in the Microsoft Knowledge Base: