DYNAMIC MODELING OF CONSTRUCTION PROJECTS' LABOR NEED

Human resource management is regarded as a fundamental process for effective labor application to ensure desired performance in the project. The project goals are met only through human resource management, and the project success relies on it. Construction is a labor-intensive industry that heavily depends on human resources. Moreover, construction projects are naturally complex and dynamics. One of the effective human resource management practices that greatly affects the project workflow and progress is to obtain required labor. System dynamics is applied to model the labor requirements of the construction projects', considering project dynamics. System dynamics is used as a research tool to provide useful insights for human resource planners to ensure that the project will be delivered on time and within the budget. The labor need of the construction projects is investigated based on project progress. A causal loop diagram is obtained, and the Stock-Flow model is developed for estimating the labor need of the construction projects. The proposed model consists of subsystems including the human resources, project workflow, project performance indexes, and policies. The required data are collected for a housing project executed in Iran. Finally, the dynamic model of the labor need of construction projects is built. The model has been validated using standard testing methods of system dynamics models. Simulation results show that the required labor in construction projects has fluctuations over time. These fluctuations affect the labor supplying process. Two policies have been proposed to reduce the fluctuations of the labor need of construction projects including hiring policy at different times and employment of different groups of the labor in terms of experience and skills. Although both policies improve the system, each one of them has different effects on project performance. By using the model, the required labor based on project progress can be determined. The opportunity can be given to decision-makers to plan for timely supply of project labor.