1. Assistant Professor, Dept. of Construction Management, Colorado State Univ., Fort Collins, CO 80523 (corresponding author).
2. Vecellio Professor, Charles E. Via, Jr. Dept. of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24061.
3. Professor and R. H. Bogle Faculty Fellow, Grado Dept. of Industrial and Systems Engineering, Virginia Tech, Northern Virginia Center, 7054 Haycock Rd., Falls Church, VA 22043-2311.