Hi,
to my experience, a schedule line can be split into multiple delivery lines, however, for a single delivery line, it can only be traced back to a unique schedule line, and for an outbound delivery document, you can find 'actual goods issue date' at header level which should be applied to each delivery line, so for any given delivery item, its actual goods issue date can be found from document header, and when traced back to a schedule line, you can also find the 'planned/confirmed goods issue date'
correct me if any, thanks