Currently, if lead time is enabled and setup in default order settings, if a user updates the PO header delivery date on a confirmed Purchase order and decides to updates the order delivery lines, the system automatically adds the lead time from the current date to the days that are setup for that item lead time in default order settings.
For example, if a confirmed PO has a delivery date of April 10th and the vendor informs the customer closer to the delivery date (April 3rd) that the order will actually be delivered on April 20. If all the items on the PO have a Purchase lead time setup to 28 days, when the PO header delivery date is updated to April 20 and Update order delivery lines is set to yes when prompted, the line level delivery date would be April 3rd +28 days which is May 1st instead of set to April 20th to match the PO header delivery date.
This causes reporting mismatches comparing delivery date on header and line level and even more importantly affects Master planning calculations as now the system net requirements shows the line level requirement date for that PO to May 1st when it is being delivered on April 20.
There is a way to manage delivery date using confirmed delivery date to update any changes but then this causes issues with the same delivery date issue persisting above - if delivery dates that do not match is shared with external stakeholders, this may be confusing.
Have a method for customers to decide whether they would like the lead time to be taken to account when confirmed PO delivery dates are changed would greatly help and ensure the same delivery date is displayed on header and line level and there are no downstream impacts to master planning.