In project deliverable, when an item is connected to a serialized manufacturing invenroty part, we have the possibility to reserve the serial n° that need to be manufactured.
So that when the Shop order is created from the deliverable item, the serial n° reservation done on the deliverable item is transferred to the SO.
When we cancel the supply request from the deliverable item - i.e. the SO is cancelled -, the serial n° reservation is not available anymore.