Plan cost in production order

Hi

Recently I have noticed the following-

I have created production order and selected Plan Cost at the time of saving production order.

While checking the plan cost system have calculated plan cost of my one of the raw material which was not in stock .

I checked the last moving average price and also purchase order but that value was not matching either to last moving average price in material master or purchase order .

Note for Moving Average price (MAP)  -  Though the stock is zero last MAP is displayed in material master . It gets overwritten when next goods receipt is posted

So my questions are

If stock is zero then system calculates the plan cost ? Yes or No

If yes then what price it pick ?

Regards

Bhushan Bivalkar