Run the Create purchase order from purchase offer process to promote the selected purchase offer to an order. The purchase offer is automatically assigned a purchase order code. If you set the relevant option, also the status of the underlying lines will be updated to 'Order'. In this case, you will specify this new status on the processing form.
To copy the offer details (such as the price) from the Purchase offer details for part form to the purchase order, select the Copy offer data to purchase line check box.
It is also possible to manually convert a purchase offer into a purchase order. To do so, manually assign a purchase order code and change the status of the purchase line you want to include in the purchase order. If there are any purchase lines you do not want to include in the purchase order, set the status of these lines to 'History'.
Note: There can only be one purchase order for an external operation: if the external operation already has a purchase line with a status of the 'Order' type, it will not be possible to convert a purchase offer line into a purchase order line for that external operation.