Multi-objective Stochastic Time-cost-quality Optimization for Construction Projects Based on the Reliability Theory

The management problem of projects has received more attention in recent years due to the trend towards increasing complexity in the construction industry. Time, cost and quality are three important aspects of project management. Thus, achieving a balance among the minimum project time, minimum project cost and maximum project quality can determine the success of a construction project. Moreover, the time of a project not only affects the cost but also the quality of the project. However, most research usually ignores the influence of the stochastic environments and considers the time of the project as a constant. Thus, this paper explores a new method to measure the stochastic time based on system reliability theory. Two stochastic time-cost-quality tradeoff optimization models are formulated for two construction projects with considering crossover operations or not, respectively. The optimization of the time reliability-cost-quality tradeoff for the project is achieved by using the particle swarm optimization algorithm. Finally, two illustrative examples are used to demonstrate the effectiveness of the two proposed models for a construction project with four activities.