The open quantity is the quantity of a material, per schedule line, due for delivery. It is calculated based on the quantities:

• Delivered to the customer
• Actually received and reported back by the customer
• Requested by the customer in the current delivery schedule

The system calculates the quantity in transit from the cumulative delivered and cumulative received quantities. If there are any quantities in transit, they are subtracted from the open quantity.

The system calculates the current open quantity for each schedule line in an incoming delivery schedule as follows:

• 1300 units have been delivered to the customer (cumulative delivered quantity)
• 1000 units have already been received by the customer (cumulative received quantity)
• 500 units have been requested by the customer for 10/01 in the current forecast delivery schedule

You first calculate the cumulative released quantity, which is the sum of the cumulative received quantity and schedule lines in the current delivery schedule. The cumulative released quantity is 1500 (1000 + 500).

You then calculate the open quantity by subtracting from the cumulative released quantity the amount that has already been delivered. The open quantity is 200 units (1500 - 1300).

Result: You deliver 200 more units.

• The customer requests an additional 600 units on 11/01

The cumulative released quantity increases to 2100 (1500 + 600). You subtract from this quantity the amount that you have delivered, which is now 1300 plus the 200 open units for which goods issue has been posted. The new open quantity is 600 units (2100 - 1500).

Result: You deliver 600 more units.

• 1300 units have been delivered to the customer (cumulative delivered quantity)
• 1000 units have already been received by the customer (cumulative received quantity)
• 50 units have been requested by the customer for 10/01 in the current JIT delivery schedule

You first calculate the cumulative released quantity, which is the sum of the cumulative received quantity and schedule lines in the current delivery schedule. The cumulative released quantity is 1050 (1000 + 50).

Since you have already delivered 1300 units to the customer, there have been more units delivered than released. The same is true for the schedule lines on 10/2 and 10/04.

Result: There are no open quantities for these schedule line dates.