Modeling the effects of production pressure on safety performance in construction projects using system dynamics.

INTRODUCTION: Construction incidents occur due to system failures, not due to a single factor such as unsafe behavior or condition. Therefore, construction safety should be investigated using a systematic view capable of illustrating the complex nature of incidents. Construction projects are also often behind their planned schedule and suffer from various pressures caused by contractual deadlines or clients. Previous studies demonstrated that such pressures negatively affect safety performance; however, the process of how production pressure influences safety performance is not fully investigated. METHOD: The present research aimed to understand the feedback mechanism of how production pressure interactively affects safety performance and safety-related managerial components in a construction project. Ground theory method (GTM) is used to create a conceptual causal loop diagram that shows the relationship between incident rate and other variables such as labor hour, actual and planned progress, safety climate, rework, and safety training. Moreover, a power plant construction project was used as a case study to practically investigate the conceptual model; a case study is employed to build a System Dynamics (SD) model. The simulation model was then validated using behavior reproduction and sensitivity analysis. RESULTS: The results of the inequality statistics show that the simulation model can be used to forecast trends in the incident rate.

Developing safety archetypes of construction industry at project level using system dynamics.

INTRODUCTION: Safe behavior and work conditions are a major concern in construction projects. However, accidents occur due to system failures, not a single factor such as unsafe behavior or condition. Construction safety should be investigated by a systematic view capable of illustrating the complex nature of accidents. METHOD: The present research aims to detect and categorize behavior patterns recurring in construction safety management continuously. Content analysis and ground theory method (GTM) were adopted to achieve the study objectives. In total, 90 articles were reviewed to explore the factors influencing safety in construction projects all over the world. Furthermore, 20 interviews were conducted on participants with rich experience in construction health and safety. Four archetypes were identified from data collection process, including delay in design, number of subcontractors, cost and safety of project, and supervisors and safety. Each archetype is completely discussed at different steps of dynamic complexity, behavior over time, and the leverage point to show how to deal with the archetype.