Printing system and control method therefor

A printing system comprising:

• an image forming apparatus configured to form images on sheets;
• a first sheet stacking apparatus including a first stacking tray to which sheets conveyed from the image forming apparatus are discharged;
• a second sheet stacking apparatus provided at a downstream side of the first sheet stacking apparatus in a conveyance direction of sheets, and including a second stacking tray to which sheets conveyed from the image forming apparatus are discharged;
• a post-processing apparatus provided at a downstream side of the second sheet stacking apparatus in the conveyance direction, and including a post-processing device configured to perform post-processing to sheets conveyed from the image forming apparatus and a third stacking tray to which sheets, to which the post-processing has been performed by the post-processing device, are discharged, wherein the post-processing includes saddle stitching;
• a receiving device configured to receive a print job in which one of the first stacking tray, the second stacking tray, or the third stacking tray is designated as a delivery destination of sheets on which images are formed by the image forming apparatus;
• and
• a controller configured to control, based on the print job received by the receiving device, the image forming apparatus to form images on sheets,
• wherein the controller is configured to obtain information indicating permission or inhibition for automatically changing the delivery destination, and
• wherein the controller is configured to control the delivery destination, based on the obtained information, so as to:
• (i) in a case where one stacking tray of the first stacking tray or the second stacking tray is designated as the delivery destination in the received print job and the obtained information indicates permission to change the delivery destination, continue execution of the print job by changing the delivery destination to the other stacking tray of the first stacking tray or the second stacking tray, in response to detecting a fully loaded state of the one stacking tray designated as the delivery destination,
• (ii) in a case where one stacking tray of the first stacking tray or the second stacking tray is designated as the delivery destination in the received print job and the obtained information indicates inhibition to change the delivery destination, suspend the execution of the received print job until sheets on the one stacking tray designated as the delivery destination are removed, in response to detecting a fully loaded state of the one stacking tray, and
• (iii) in a case where the third stacking tray is designated as the delivery destination in the received print job, suspend the execution of the received print job until sheets on the third stacking tray are removed, in response to detecting a fully loaded state of the third stacking tray, regardless of whether the information indicates permission or inhibition of changing the delivery destination.