Introducing a system dynamic–based model of quality estimation for construction industry subcontractors' works

Construction project managers usually involve with selecting the most suitable subcontractors (SCs) to improve the overall quality of the construction process. In this paper, a system dynamics-based approach is introduced for SC selection process which is modeled considering a complex inter-related structure of different factors influencing the SCs' work quality (SWQ). To this aim, cause and effect feedback loops are used to build a qualitative model (causal loop diagram). Afterward, the relationships among various factors are determined by using the expert's judgment to construct the quantitative model (stock and flows diagram). Finally, the model is evaluated by applying a real construction project and also evaluated by carrying sensitivity analyses on different factors. The developed model is expected to help the general contractor in making a fair judgment to assess the SWQ during the execution time of activities as well as before the beginning of the work packages.