A processing system may include a server group connectable to an image forming apparatus, a request processing unit, a backend processing unit, a receiving unit, a determination unit, and a sending unit. The receiving unit receives information relating to a document file corresponding to a processing request from the image forming apparatus. If the determination unit determines that that the processing method is a synchronous processing method, then the request processing unit processes the document file based on the processing request. If the determination unit determines that that the processing method is an asynchronous processing method, then the request processing unit requests the backend processing unit to process the processing request. After the document file has been processed according to the determined processing method, the sending unit sends a notification to the image forming apparatus that the document file has been processed.