In project management a variance is the difference between a planned cost and the actual cost incurred and, normally, this leads to corrective actions. A more general definition of Variance Analysis can be found in Wikipedia and in many other web sites that specialize in this topic.

**Variance Analysis**

__At Time Now__:
E

_{i}**= Initial Estimate (Planned or Estimated Budget)**
Actuals = A
= Actual amount incurred

E

_{t-c}= Estimate To Complete
E

_{a-c}_{ }= Estimate At Completion = A + E_{t-c }
V

_{a-c}= Variance At Completion = E_{i }- E_{a-c}_{ }

__At New Time (Time Now + T)__:
If the variance is high (too much error or discrepancy), then it will be appropriate to assign E

_{a-c}as the new E_{i. }
Hence,

E

_{i (new time)}= E_{a-c (time now) }