Resumo (PT):
Finding a first feasible solution is a very difficult task for a variety of problems. In some cases, it is the only goal. In this paper, we present a genetic algorithm (GA) to solve the multi-item capacitated lot sizing and scheduling problem with sequence dependent setup times and costs. It is a hard and important optimization problem that often arises in industry. When considering highly constrained problems, commercial solvers fail even to find a feasible solution. We develop new features that enable the GA to deal with feasible and infeasible solutions, based on the
concept of nested domains. The expansion of the domain is done by bands, which represent additional overtime. Within each band, the solutions are only differentiated
by the value of the objective function (fitness). Throughout generations, the amplitudes of the bands are dynamically updated to improve the convergence towards
the feasible domain. Different approaches to this end are discussed. Computational results show the efficiency of the GA approach in finding feasible solutions for highly capacitated instances.
Language:
English
Type (Professor's evaluation):
Scientific