Software systems have to provide flexibility by implementing variability. Existing design methodologies do not support means for optimizing the design for variability and for measuring the overhead effort. Therefore, the solutions cannot be optimized regarding a minimal overhead for variability. Other methods are lacking of a traceability for variability mechanisms, or do not provide means for measuring and optimizing solutions. The paper introduces traceability links for variability with a special emphasis on support for implementation, build and deployment, and presents guidelines for optimizing the design with indicators for evaluating the results. The feasibility of the approach is shown by a case study from an industrial setting.