The purchase order line is closed automatically when all receipt lines corresponding to it are in the Received status or when the received quantity of the purchase order line is within the specified closing tolerance. This assumes that the automatic order closing function is enabled for the purchase part.
A purchase order line might need to be closed manually if, for example, it is determined that the supplier cannot deliver the entire order or when the automatic order closing function is not activated.
The purchase order line is closed and the status is updated to Closed.