Mathematical Optimization in Flexible Job Shop Scheduling

The major theme of this thesis is the mathematical optimization modelling of the flexible job shop scheduling problem. This problem is present in the so-called multitask cell—a production cell at GKN Aerospace’s facility located in Trollhättan, Sweden—which has served as a case study during the work with this thesis. The thesis consists of two parts, of which the first consid-ers the major theme which runs through the first three appended papers. The second part of the thesis corresponds to the fourth appended paper and deals with the computational complexity of flow shop scheduling problems with deteriorating jobs. The basic flow shop scheduling problem is a special case of the flexible job shop scheduling problem. In the first paper, two mathematical optimization models are formulated for the general flexible job shop scheduling problem. One of the models—a so-called time-indexed model—is incorporated into an iterative procedure, which is then shown to solve instances of the proble