Activating Availability Control with Budget Allocation 
Use
In the budget profile, you selected Activation type 1 for availability control. This means that the availability control is automatically activated when you make entries (or release budget, if this is to be checked).
Availability control is always defined for a particular budget profile, and you need to define a tolerance limit for at least one business transaction group for the budget profile. Once you enter a budget for a project with the corresponding budget profile, the availability control is activated.
Note
For technical reasons, availability control cannot be activated automatically for hierarchical projects (assigned to an investment program) when budget is allocated from the investment program item to the assigned WBS element. Activation follows automatically during the first background activation run or during further allocation in the project. Availability control for internal orders from existing projects for top WBS elements is activated automatically during budget allocation of investment program items.