If overallocated resources exist in a project plan, the resources will not be able to complete all their assignments in the scheduled time period. Some of the assigned work will not be completed within that time period ”either the work will not be done, it will not be done thoroughly, or it will have to be done at a later time. If the work is never done or is not done well, the full scope of the project delivery will not be realized. If the work is done later, the project finish date might be delayed and cause you to miss the final deadline.
You can resolve an overallocation by looking for ways to do either or both of the following:
Increasing Availability of Overallocated Resources
Remember that the availability of a resource during any time period depends on the settings in both the Resource Availability table in the Resource Information dialog box and the Resource Calendar (the Working Time tab). If you want to try to increase the availability of an overallocated resource, you can try the following:
The Resource Availability table in the Resource Information dialog box lets you define when the resource is available and how many units are available during each time period. The resource is overallocated if the assigned units exceed the available units for any time period. You might be able to change the available units for the period to encompass the overallocated assignment. The units available are typically 100% (or 1 unit) for individual resources and a larger number than that for group or team resources. If an individual resource has less than 100%, you can see if the resource can work full-time . If a group resource is overallocated, you can increase the number of units available by adding more units to the group.
Although part-time workers can be given a Max Units Available setting of less than 100% to show that they are part time, it is generally best to enter the units as 100% and modify their available working hours on the calendar to reflect exactly when they are available each day. That way, they are available 100% during the hours when they are scheduled to work. If a part-time resource uses flexible working hours, however, and works at different times as needed, you could give that resource a regular 8- hour calendar setting and enter 50% in the Max Units field.
If additional workers have to be hired to increase the number of units, you must consider the substantial added costs of searching, hiring, increased payroll, fringe benefits, and all the other factors associated with permanent employment. This solution is generally not feasible unless there is a demonstrated need for a permanent increase in the employment roster. If additional workers can be added as temporary employees , the added cost is probably less than the cost of a permanent hire, but it still must be figured into the decision. If the group resource is already made up of nonemployees ”for example, contract workers or workers supplied by a vendor for an outsourced task ”requesting additional units to work during the peak demand time is not necessarily an added cost to the project. If those workers were going to be paid for completing this task anyway, although over a longer duration, you could just as easily pay them for a shorter duration to meet the demand.
If the overallocation is not substantial, you can see whether the resource is willing to work more hours during the period of overallocation. One way to show this in Project is to schedule overtime hours for the overallocated resource. Overtime hours are charged to the task at the overtime rate defined for the resource and, therefore, potentially increase the cost of the task because Project substitutes these hours for hours during the regular calendar hours.
Alternatively, you can temporarily increase the working time by changing the working hours on the resource calendar during the overallocation time period. You should use this alternative instead of assigning overtime when the resource is not paid a premium-wage rate for working overtime. You can control exactly when the additional hours are available by using this solution, but you cannot specify when overtime hours will be worked in the schedule.
As in earlier releases of Project, in Microsoft Project 2003 you cannot schedule overtime hours for specific dates or time periods. You assign the resource to work overtime on a specific task, and Project schedules the overtime work. Project spreads the overtime evenly over the duration of the task. When tracking actual work, you can, however, record the actual overtime work in the time period when the work was done.
A quick way to view overallocations and to establish their impact on your project is to use the Resource Usage view in the top pane and the Gantt Chart view in the bottom pane. If the Gantt Chart view is formatted to show critical and noncritical tasks, you can easily see which tasks will affect the project (critical tasks) and which tasks could be delayed, moved, or extended without necessarily affecting the project. If, as a result of a change, a task becomes critical, you know that you need to undo this and find an alternative solution.
Using this combination view also helps when you're considering replacing or substituting resources because adding a resource to a critical task can reduce a task's duration and thereby reduce the project's duration. In addition, removing resources from a noncritical task might enable you to extend that task without affecting the project. But this reduction could remove an overallocation. Extending this logically, you might conclude that it is possible to remove a resource from one task ”say, a noncritical task ”and add it to a critical task. This has the effect of more efficiently utilizing the resources that are available in the project.
For the steps to display critical tasks, see "Formatting the Gantt Chart View," p. 790 .
Reducing the Workload for an Overallocated Resource
If a resource has peaks of activity that result in overallocations, you can remove the overallocations by leveling ”that is, by reducing the workload during the peaks to level out the amount of work expected from the resource. To reduce the workload for a resource in an overallocated period, you can do the following:
Reduce the total work defined for one or more task assignments during the period.
Reduce the number of tasks assigned to the resource during the period.
Shift the workload for one or more assignments to other periods by delaying assignments or by changing the contour of assignments to move work to later time periods.
Reducing the total work defined for a task can help ease the overallocation for the resources assigned to the task. This reduction might result from lowering the performance requirements for completing the task, removing unnecessary work from the task definition, or reassessing the work estimate for completing the task. But you must consider the effect of this downscaling of the project on the scope and goal expectations of the project.
You can reduce the number of tasks assigned to the resource during the overallocated period in several ways:
You can cancel one or more tasks. This option may reduce the scope of the project's delivered outcome. But, depending on the extent to which the task list includes unnecessary elements, you have some latitude in removing tasks without seriously affecting the project scope.
You can substitute other resources for the overallocated resource in the assignments for the task. This is frequently the most satisfactory solution for resolving resource overallocations. However, this solution requires you to do more investigative work.
You can keep the resource assigned to all the tasks if you can postpone or delay the assigned work for some of the tasks to a later period, when the resource has more availability to perform that work. Delaying any assigned work in the project schedule naturally extends the duration for the task and may compromise finishing the overall project on time.
To delay some or all work on an assignment, you can try one of the following strategies:
You can delay one or more tasks to start at a later date in order to free the overallocated resource to work on higher-priority tasks. This may not be a viable option when deadlines are important because delaying tasks can extend the project finish date. If critical tasks are delayed, the project finish date is delayed. See the section "Delaying a Task," later in this chapter.
Instead of delaying the entire task, and therefore delaying the assignments for all resources assigned to that task, you can delay just the overallocated resource's assignment on a task. Other resources can continue to work as scheduled, and the overallocated resource will do his or her part later in the project. See the section "Delaying Individual Assignments," later in this chapter.
If work on the task has already begun, you can split the task to stop work temporarily, thus freeing the resource for other tasks during the overallocation period. Splitting the task stops work for all resources assigned to the split task. This does not change the task duration or the total work for the task. See the section "Splitting a Task," later in this chapter.
Instead of splitting the task, and therefore interrupting all resource assignments for the task, you can split just the assignment for the overallocated resource, thus leaving other resources to continue their work as originally planned. This increases the duration of the task, but it does not increase the total work for the task. See the section "Splitting Individual Assignments," later in this chapter.
You can change the contour of the overallocated assignment, to move more of the work to later time periods. The default assignment contour is the Flat contour, which means work is evenly distributed throughout the duration of the task. You can choose one of several other predefined contours that set higher workloads at later points in a task's schedule. You can also edit the resource's work assignment on each task yourself, to reduce the workload during the overallocated time period. See "Extending the Available Hours on the Resource Calendar," later in this chapter, for more information.