Method for processing slaughtered poultry, wherein oven-ready carcasses of slaughtered poultry are conveyed by a feed conveyor, said feed conveyor having an endless track and carriers that are moved along said track, the feed conveyor carrier being adapted to support one carcass suspended from its legs, wherein each individual carcass is subjected at least one of: - a determination of the individual carcass weight by a weighing device, - a determination of the individual carcass size by an imaging device, wherein for dividing the carcasses into parts use is made of a first cut-up line and a second cut-up line, wherein each cut-up line has an associated cut-up line conveyor (11, 21), said cut-up line conveyor having an endless track and carriers (11 a, 21 a) that are moved along said track, each cut-up line conveyor carrier being adapted to support one carcass suspended from its legs, wherein each cut-up line comprises one or more cutting devices (12, 22) arranged along the track, which one or more cutting devices divide a carcass supported by a cut-up line conveyor carrier into parts, wherein a first transfer device is arranged between the feed conveyor and the first cut-up line conveyor and transfers carcasses from said feed conveyor to said first cut-up line conveyor, wherein a second transfer device is arranged between the feed conveyor and the second cut-up line conveyor and transfers carcasses from said feed conveyor to said second cut-up line conveyor, wherein use is made of a computerized production control system which - based upon the determination of each individual carcass made by the weighing device and/or by the imaging device - grades each of the carcasses conveyed by the feed conveyor into a category: - a small carcass size category, - a large carcass size category, wherein the production control system controls the first transfer device such that carcasses in the small carcass size category are transferred - to the greatest extent possible - from the feed conveyor to the first cut-up line conveyor, wherein the production control system controls the second transfer device such that carcasses in the large carcass size category are transferred - to the greatest extent possible - from the feed conveyor to the second cut-up line conveyor, characterized in that the computerized production control system grades each of the carcasses that are conveyed by the feed conveyor and are to be processed on one of the two cut-up lines into one of three categories: - said small carcass size category, - said large carcass size category, and - an intermediate carcass size category, and in that the computerized production control system determines in real-time - for the combination of the first transfer device and the first cut-up line conveyor and for the combination of the second transfer device and the second cut-up line conveyor - the capacity of each of said combinations to receive carcasses of the respective small carcass size and large carcass size category from the feed conveyor, and in that the production control system determines in real-time - for the combination of the first transfer device and the first cut-up line conveyor and for the combination of the second transfer device and the second cut-up line conveyor - the respective remaining capacity to receive carcasses from the feed conveyor in the situation that the carcasses in the small carcass size and large carcass size categories have - to the greatest extent possible - been allocated to the respective combination, and in that the production control system controls the first and second transfer devices (5,15) such that the carcasses in the intermediate carcass size category are distributed over said combinations on the basis of the determined remaining capacity of each of said combinations. - a determination of the individual carcass weight by a weighing device, - a determination of the individual carcass size by an imaging device, - a small carcass size category, - a large carcass size category, - said small carcass size category, - said large carcass size category, and - an intermediate carcass size category,