System reliability optimization model for construction projects via system reliability theory

For years, the construction industry has had a poor reputation for its low quality products. Although system reliability optimization (SRO) is a thought-provoking subject, little of success has arisen from its applications to the construction industry. The aim of this study is to enhance the quality of project performance through SRO. A system reliability theory based SRO model is proposed. First, a construction project is viewed as a system. The main construction activities are defined and grouped into work packages. Second, according to the physical arrangements among each work package, the reliability structural function is determined. In addition, the project quality is quantified by applying the reliability concept and the nonlinear cost-reliability function is set up. Third, the objective function and project constraints are defined. The Levenberg–Marquardt plus Universal Global Optimization method is employed for the optimization process. Finally, the maximum system reliability is generated, along with the optimal reliability and cost distributions of each work package. A real construction case is used to evaluate the workability of the proposed SRO model and the results fully prove its validity and practicality. The main contribution of the study is successfully bringing in the reliability concept and applying SRO in quality optimization for construction projects.