1. A system comprising: a printing apparatus; and a post-processing apparatus, wherein the post-processing apparatus includes: a post-processing unit configured to perform post-processing on a product printed by the printing apparatus, and a transmission unit configured to transmit, to the printing apparatus, instruction information instructing the printing apparatus to perform print processing for a first job preferentially, and wherein the printing apparatus includes: a printing unit, a reception unit configured to receive, from the post-processing apparatus, the instruction information instructing the printing apparatus to perform the print processing for the first job preferentially, and a control unit configured to perform control in such a manner that the printing apparatus performs the print processing for the first job preferentially over print processing for a second job, based on the instruction information.