Design Details: Variance
Variance is defined as the difference between the actual cost and the standard cost, as described in the following formula.
actual cost – standard cost = variance
If the actual cost changes, for example, because you post an item charge on a later date, then the variance is updated accordingly.
Note 

Revaluation does not affect the variance calculation, because revaluation only changes the inventory value. 
Example
The following example illustrates how variance is calculated for purchased items. It is based on the following scenario:

The user purchases an item at LCY 90.00, but the standard cost is LCY 100.00. Accordingly, the purchase variance is LCY –10.00.

LCY 10.00 is credited to the purchase variance account.

The user posts an item charge of LCY 20.00. Accordingly, the actual cost is increased to LCY 110.00, and the value of the purchase variance becomes LCY 10.00.

LCY 20.00 is debited to the purchase variance account. Accordingly, the net purchase variance becomes LCY 10.00.

The user revalues the item from LCY 100.00 to LCY 70.00. This does not affect the variance calculation, only the inventory value.
The following table shows the resulting value entries.
Determining the Standard Cost
The standard cost is used when calculating variance and the amount to capitalize. Since the standard cost can be changed over time because of manual update calculation, you need a point in time when the standard cost is fixed for variance calculation. This point is when the inventory increase is invoiced. For produced or assembled items, the point when standard cost is determined is when the cost is adjusted.
The following table shows how different cost shares are calculated for produced and assembled items when you use the Calculate Standard Cost function.
Cost share  Purchased item  Produced/Assembled item 

Standard Cost 
SingleLevel Material Cost + SingleLevel Capacity Cost + SingleLevel Subcontrd. Cost + SingleLevel Cap. Ovhd. Cost + SingleLevel Mfg. Ovhd. Cost


SingleLevel Material Cost 
Unit Cost 

SingleLevel Capacity Cost 
Not applicable 

SingleLevel Subcontrd. Cost 
Not applicable 

SingleLevel Cap. Ovhd Cost 
Not applicable 

SingleLevel Mfg. Ovhd Cost 
Not applicable 
(SingleLevel Material Cost + SingleLevel Capacity Cost + SingleLevel Subcontrd. Cost) * Indirect Cost % / 100 + Overhead Rate 
Rolledup Material Cost 
Unit Cost 

Rolledup Capacity Cost 
Not applicable 

Rolledup Subcontracted Cost 
Not applicable 

Rolledup Cap. Overhead Cost 
Not applicable 

Rolledup Mfg. Ovhd Cost 
Not applicable 