Availability check in production orders

Hi,

My client requirement

I have unrestricted stock of 10 no. along with number for PR & Purchage order.

In each production order the material required is 10.

I have created two production orders.

In the frist production order when i check for availability for material then system showing message all materials are available.

For second order when i check for availability for material then system showing message all materials are available.

My requirement is system should take only unrestricted stockand Once it is commited to one order it should show material shorthae to all production orders.

I am using Discrit manufacturing with make to stock strategy.

Please suggest how to find go for availability check for more then one production orders

I know t. Code is COMAC.

Regards,

S.K