Two cooperative models for the problem based on Constraint Programming arc proposed. The first is used to model the scheduling constraints, while the second is a muhipath model used for setup optimization. Integrating lower bounding techniques for the sum of setup times, the multi-path model perforins propagation based on reduced cost fixing. A solution method based on a two phase algorithm is described,,'rod a computationM study is performed both on instances known from literature as on newly proposed instances. It is shown that the cooperation of the two modelsignificantly improves performance.