1. Assistant Professor, Dept. of Industrial Engineering, King Saud Univ., P.O. Box 89885, Riyadh 11692, Saudi Arabia.
2. Assistant Professor, Dept. of Management, Radford Univ., P.O. Box 6954, Radford, VA 24142 (corresponding author).
3. Professor, Dept. of Engineering Systems and Environment, Univ. of Virginia, 151 Engineers Way, P.O. Box 400747, Charlottesville, VA 22904.