Multiobjective Optimization of Resource Leveling and Allocation during Construction Scheduling

Construction scheduling techniques often generate schedules that cause undesirable resource fluctuations that are inefficient and costly to implement on site. This paper presents the development of a novel multiobjective optimization model that is capable of measuring and minimizing these undesirable resource fluctuations to maximize resource utilization efficiency and minimize project duration while complying with all precedence relationships and resource availability constraints. The model incorporates three main modules: (1) a startup module that calculates lower and upper bounds for the model decision variables; (2) a scheduling module that generates practical schedules and evaluates their performance; and (3) a multiobjective genetic algorithm module that searches for and identifies optimal schedules. The model is integrated in a commercially available software system to facilitate its use and adoption by construction planners. An application example is analyzed to illustrate the use of the model and demonstrate its new and unique capabilities in generating optimal trade-offs between maximizing resource utilization efficiency and minimizing the duration of construction projects. DOI: 10.1061/(ASCE)CO.1943-7862.0000368. (C) 2011 American Society of Civil Engineers.