1. Professor, Univ. de Piura, Faculty of Engineering, Apartado Postal 561, Piura, Peru.
2. Associate Professor of Practice, Myers-Lawson School of Construction, Virginia Polytechnic Institute and State Univ., Blacksburg, VA 24061.
3. Eminent Scholar Emeritus, Del E. Webb School of Construction, Arizona State Univ., Chandler, AZ 85246 (corresponding author).