The challenge of exploiting weak symmetries

In contrast to a proper symmetry, a weak symmetry acts only on a subset of the variables and the weakly symmetric equivalent solutions preserve the feasibility state only with respect to a subset of the constraints. Therefore, breaking weak symmetries on the whole problem with standard techniques would lead to a loss of solutions. Weak symmetries occur in different application fields like planning, scheduling and manufacturing as well as in the fields of soft constraints. We introduce a technique that enables us to exploit weak symmetries and state experimental results on a real world problem to show the gain in using this technique.