Many customers look at the Task Assignment Actual Cost and the ACWP values. Sometimes the value on the this field is lower than the expected Actual Cost.
Many times the reason for the lower amount is because there is a past date in the Project 'As Of Date'.
Remove the date or set it to the current date and execute the 'Update Earned Value Totals' job.
Here are more details on this field:
ACWP: Actual Cost of Work Performed
ACWP: Sum of the actuals on the project through a point in time. That point in time is the Project As Of Date, if set, else the current system date. If you have future posted actuals, they will not be included in this calculation unless your As Of date is at or beyond the last date of posted actuals.
Baseline Required: No
Detail Task Level: ACWP = Sum of all assignment Actual Cost values for the task
Summary Task: ACWP = Sum of ACWP for Child Tasks
Project Level: ACWP = Sum of ACWP for all Level 1 Summary Tasks