Exploratory structural equation modeling to analyze bridge projects cost overruns due to variation orders

Purpose The purpose of this study is to identify the specific causes of variation orders that affect project costs, as perceived by relevant stakeholders, including contractors, consultants, and clients. Variation orders are considered one of the significant contributors to cost overruns in construction projects. That is why various research efforts have addressed this issue to tackle its impact on construction projects. However, most of these studies have focused on various project types, giving little attention to large-scale infrastructure projects such as bridges. As a result, to address this gap, this study adopts a structural equation modeling (SEM) to investigate the primary causes of variation orders that lead to cost overruns in construction bridge projects. This is accomplished by identifying variation order causes through a comprehensive literature review, in addition to collecting data from eight actual bridge projects in Egypt. Design/methodology/approach The research methodology involves the identification of the main causes of variation orders on cost overrun in bridge construction projects using an extensive literature review and structured questionnaires. First, an initial set of 51 potential variation order causes was identified. Then, interviews were conducted with eight experts to discuss the relevance of the identified causes to the cost overruns in bridge construction projects in Egypt. Consequently, the refined list of 51 causes served as the foundation for a structured questionnaire survey, which was distributed to 95 experienced professionals specializing in bridge projects in Egypt. Consequently, the responses were analyzed to identify the most significant causes, which consist of thirty main causes, using mean scores as the criterion for ranking. To investigate the underlying relationships among these causes, SEM was conducted using AMOS software. This analysis determined the correlations and interactions of latent variables within a multidimensional performance framework, providing deeper insights into how these causes collectively contribute to project cost overruns. Findings Using SEM, 19 key variation order causes were identified as significantly affecting bridge construction cost overruns. The aforementioned causes were classified into four latent variables, which form the foundation for eight hypotheses aimed at examining both the interactions among the variables and their impact on cost overruns. The analysis confirms the importance of 19 factors contributing to rising project costs, underlining the complex nature of variation orders in Egyptian bridge construction. Additionally, a case study of a real bridge project is provided that illustrates how these latent factors impacted the cost overruns. This case study acts as a tangible example highlighting the importance of these factors in managing cost performance in bridge construction. Originality/value This study uses structural equation modeling to identify the primary causes of variation orders resulting in cost overruns within Egyptian bridge construction projects. In contrast to previous research efforts that focused on various types of construction projects, with minimal attention given to bridge construction projects, this research specifically examines bridge projects by integrating practical insights, expert evaluations and thorough statistical analyses. Its value lies in providing assistance to practitioners in improving decision-making, reducing risks and enhancing cost management in bridge projects.