The paper outlines a case study where the PYA-method (production yield analysis) was implemented at a poultry-slaughtering line, processing 9000 broiler chicks per hour. It was shown that the average live weight of a flock of broilers could be used to predict the maximum production yield of the parts (fillet, legs, wings, etc.). For all parts a strong linear relationship for the weight of the parts with the average live weight (LW) was found. Significant differences (P less than or equal to 0.05) between the strains Ross 308 and 508 were observed. Ross 308 showed significant higher yields for feet, guts and lungs, heart (LW < 1626.2 g), skinned gizzard, neck without skin, tail (LW > 1907.4 g), skeleton frame of the breast, saddle and legs. Ross 508 showed significant higher yields for chilled carcass, heart (LW > 1626.2 g), tail (LW < 1907.4 g), breast, fillet and upper back. The Yield Indexes that were calculated for the various parts varied between 0.5 and 1.0 and showed remarkable potentials for yield improvement. Yield improvements were realised by many actions like: good housekeeping, training and instructing of employees, fine-tuning of equipment and replacement of out dated machinery or parts of it. (C) 2004 Elsevier Ltd. All rights reserved.