1. Professor, Dept. of Construction Engineering, Universitat Politècnica de Catalunya, C/Colom, 11, Ed TR-5, 08222 Terrassa, Barcelona, Spain (corresponding author).
2. Ph.D. Student, Dept. of Construction Engineering, Universitat Politècnica de Catalunya, C/Colom, 11, Ed TR-5, 08222 Terrassa, Barcelona, Spain.
3. John Curtin Distinguished Professor, Dept. of Construction Management, School of Built Environment, Curtin Univ. of Technology, GPO Box 1987, Perth, Western Australia 6845, Australia.