A Variance at Completion ( VAC) threshold value is expressed as a monetary value. An issue is generated if the Variance At Completion (the budgeted or planned total cost - latest total cost estimate) falls beyond the threshold values.
Variance At Completion may also be expressed as VAC = Budget at Completion ( BAC) - Estimate At Completion ( EAC).
A negative value indicates an estimated total cost overrun. If the threshold value is 0, an issue is generated as soon as the latest estimate for total cost exceeds the budgeted or planned total cost. A larger negative value for a Variance At Completion threshold indicates that a certain amount of estimated total cost overrun may be tolerated before an issue is generated.