Logistic regression analysis for factors influencing cost performance of design-bid-build and design-build projects

Purpose The purpose of this paper is to explore the influencing factors of cost performance of design-bid-build (DBB) and design-build (DB) projects and comparing the differences of influencing factors between these two delivery methods. Design/methodology/approach This research identified and refined 14 influencing factors through literature review and academic expert discussions. Questionnaire survey was conducted to collect data about the influencing factors and project cost performance. Then those factors were reduced to four components by factor analysis. Logistic regression analysis is used to investigate the relationship between four principal components and project cost performance. Findings The results indicate that the significant influencing factors of project cost performance of DBB projects and DB projects are different. For DBB projects, owner abilities, such as owner team ability, owner experience, and owner finance, are important influencing factors causing cost overruns, while for DB projects cost performance is more sensitive to the contractor abilities, namely, contractor team ability, contractor finance, contractor experience, etc. Research limitations/implications The results of the paper are mainly derived by quantitative research method based on the survey of 144 samples, so the results may need validation by qualitative studies. Further research could apply case study or interview to validate the findings in this research. In addition, project type and location are not considered as control variables due to the limited number of samples, future research could be conducted to investigate their relationship with project performance. Practical implications The findings of this research not only help practitioners have a better understanding of the factors influencing project cost performance, but also provide some guidelines for practitioners to pay attention to different factors to better control the cost performance within different delivery systems. Originality/value Owner ability and contractor ability are found to be of different importance in influencing cost performance of DBB and DB projects. This research extends previous research on cost management by considering different significant factors in influencing project cost performance within DBB and DB projects.