Restricting Purchase requestions based on a Budget

Hi,

There is a customer requirement (Construction project) to restrict creating purchase requestions if the budgeted quantity exceeds. 

As an example ,  a budget of 10,000 cement bags has been allocated for a specific construction project. The project execution team has been utilized 10,000 allocated cement bags and the team try to create a new purchase requestion to buy more 100 cement bags. 

In this case system needs to restrict creating a new PR since the budgeted 10,000 units of cement bags exceeds by this PR. 

Appreciate help on this matter. 

Thanks,

Dulanjana