If your assigned work resources (people and equipment) are associated with cost rates or per-use costs, when you enter progress information on their tasks or assignments, actual costs are calculated along with actual work.

If you entered costs for material resources, actual costs are also calculated based on the completion of the task.

If you need to, in the Actual Work field, you can change the value for the material by specifying the amount of material actually used. Material is measured by its material label—for example, board feet, cubic yards, or cartons—while the Work and Actual Work fields use a time unit such as hours or days for work resources. However, you can edit the Work or Actual Work fields for material resource assignments in the Task Usage view or Resource Usage view or on the Tracking tab in the Assignment Information dialog box, as shown in Figure 11-18.

Figure 11-18. You can enter the actual amount of material used or the actual cost for the material on the Tracking tab in the Assignment Information dialog box.

When you specify a percentage complete for a task, the work amount and costs for any assigned work and costs for any material resources are calculated automatically, as are any fixed costs associated with the task.

However, any assigned cost resources are not included in this automatic calculation of actual costs. You can enter progress for cost resources only on the assignment level. To do this, follow these steps:

When you enter progress information on a task that includes a fixed cost, the actual fixed cost is calculated with the progress according to the accrual method you selected (start, finish, or prorated).

If a fixed cost has changed from your original setting, simply change the amount. In a task sheet, apply the Cost table, and then change the amount in the Fixed Cost field for the task.

If resources are assigned to tasks in your project plan, and those resources also have their costs entered in Project 2010, costs are updated whenever you enter actual progress information. For example, suppose that a $25/hour resource is assigned to 8 hours of work on a task. When you specify that the task is 50 percent complete, $100 of actual cost is recorded for this task.

If you do not want Project 2010 to calculate costs for you in this manner, you can turn off this option and enter costs yourself. To turn off automatic cost calculation, follow these steps:

After you turn off automatic cost calculation, you can enter task costs manually. To do this, display a task sheet. On the View tab, in the Data group, click Tables, and then click Cost to apply the Cost table. Enter total actual costs in the Actual field for the task.

To manually enter timephased costs for tasks or assignments, display the Task Usage view. On the Format tab, in the Details group, click Actual Cost. The Actual Cost field is added to the timephased portion of the view. Enter timephased actual costs in the appropriate cells.