Schedule Line Question

Greetings,

I have a question regarding Schedule Lines in a Sales Order.

I'm currently looking at a Sales Order with 1 line item. When I drill into that line item and go to the Schedule Line tab, I see 24 Schedule Lines. In the first 16 Schedule Lines, the "Delivered Qty" is equal to the "Order Qty", however when I run VA05 for Open Orders only, all 24 Schedule Lines appear. I am a Production guy and not fully familiar with the Sales module, and would like to know why VA05 for Open Orders is showing delivered Schedule Lines. What tag is required for SAP to recognize a Schedule Line as complete?

Thanks