Shortage Check Availability Check

If the availability check is carried out without the cumulative confirmed quantities or requirement quantities being taken into account, this can lead to more being confirmed than is available. The system checks whether ATP quantities arise in the period before the delivery date. If so, the new sales order reduces the ATP quantities if the ATP dates come befor the delivery date.

If a planned inward movement of goods is delayed to a desired date after the confirmed date, then the confirmation of the sales order remains in place without a stock coverage being given. This is because a change to inward movement of goods does not necessarily change the order. In this situation, a newly created order could be confirmed because of the delayed inward movement of goods and lead to more being confirmed than is available.

Situation 1

Inward/outward moverment	Quantity	ATP quantity	Cumulative ATP quantity	Confirmed quantity
Stock	100	0	0	-
Planned order	100	0	-100	-
Sales order 1	-200	-	-	-200

Situation 2

Inward/outward moverment	Quantity	ATP quantity	Cumulative ATP quantity	Confirmed quantity
Stock	100	0	0	-
Sales order 1	-200	-100	-100	-200
Planned order	100	0	0	-
Sales order 2	-100	-	-	-100

In Situation 1, the first sales order is confirmed for its full quantity for a point in time before the planned order. In Situation 2, the planned order has now been delayed until after the delivery date for sales order 1. For the new sales order 2, the availabililty check reports an ATP quantity of 100, as the full quantity of the deferred planned order is still available and, according to this checking logic, sales order 1 cannot be supplied by this inward movement of goods.

The example shows how an error is caused in confirmation by the deferring of a planned order. This causes the total of the confirmed quantities to exceed the total of all inward movement of goods.

There are three possible ways of avoiding this error:

• Carring out a planning run

• Rescheduling

• Backorder processing

Since these functions are very time consuming, it is possible for orders to be delivered that should not be delivered at all according to their entry data. The shortage check is used to avoid this situation.

You can define how the availability check is carried out under Define checking group in SD Customizing. The options are as follows:

• Set up check to take cumulative confirmed quantities into account

The system takes into account the total of all confirmed quantities when calculating the cumulative ATP quantity. This means that new sales orders can only be confirmed if the total for inbound goods is greater than the total for confirmed quantities.

We recommend that you work with the cumulative requirement quantities when you create sales orders.

• Set up check to take cumulative requirement quantities into account

The system takes into account the total of all open requirement quantities when calculating the cumulative ATP quantity. This means that new sales orders can only be confirmed if the total for inbound goods is greater than the total for requirement quantities.

We recommend that you work with cumulated confirmed quantities when you change sales orders.