A mounting condition determining method including: obtaining mounting information including information related to component mounting operations scheduled to be performed by a mounter (S1); judging, using the mounting information obtained in the obtaining: which production mode between a synchronous mode and an asynchronous mode is suitable for the scheduled component mounting operations; or which production mode between an alternating mode and an independent mode is suitable for the scheduled component mounting operations (S2, S3); and selecting the production mode indicated by a result of the judgment in the judging, as the production mode to be executed by the mounter (S5, S6).