Hi Vijay,
This is possible using dynamic credit check. please perform the below steps in SPRO --> SD --> basic settings --> credit Management.
1. Define a credit group.
2. define risk category and assign it to customer credit master FD32.
3. Assign the credit group to the order/delivery type(OVAK , OVAD) . In credit check field select automatic credit check.
4. In OVA8, maintain the combination (credit control area, credit group, risk category).
5. For credit limit for number of days -- Choose the option dynamic credit check, open item , and fill the fields max open item % and no. of days open.
6. For financial credit lime -- Give the credit limit in customer credit master FD32.
Try this and let us know the results.
Thanks
Manoj