How the Credit Exposure will be calculated?

Hi Gurus,

I have done the settings for dynamic credit check.I have maintained the credit limit in FD32 $10000.but when i was created the first sales order for net value $ 15000 for new customer,Credit check is not happening.After creating the order I have checked the credit exposure,it is showing $900 only.Actually first order document value is $15000 and credit limit is $10000.but it is showing credit exposure is $900,Where this calculation (credit exposure)is been done? where do i need to check?

if I am right the document value is $15000,the same should be replicate in exposure?if worng please guide me to solve this issue.

Proper solution is rewarded.

Regards

Venkat