1. Department of Environmental Engineering, Technical University of Denmark (DTU), DK-2800 Lyngby, Denmark,
2. Department of Management Engineering, Technical University of Denmark (DTU), DK-2800 Kgs. Lyngby, Denmark, and
3. The Interuniversity Research Centre for the Life Cycle of Products, Processes and Services (CIRAIG), École Polytechnique de Montréal., P.O. Box 6079, Montréal, Québec H3C 3A7, Canada