On the duration and cost variability of construction activities: an empirical study
journal contributionposted on 22.11.2019 by Pablo Ballesteros-Perez, Enoc Sanz-Ablanedo, Robby Soetanto, M. Carmen Gonzalez-Cruz, Graeme D. Larsen, A. Cerezo-Narvaez
Any type of content formally published in an academic journal, usually following a peer-review process.
The unique nature of construction projects can mean that construction activities often suffer from duration and cost variability. As this variability is unplanned it can present a problem when attempting to complete a project on time and on budget. Various factors causing this variability have been identified in the literature, but they predominantly refer to the nature and/or context of the whole project, rather than their specific activities. In this paper, the order of magnitude of and correlation between activity duration and cost variability is analyzed in 101 construction projects with over 5000 activities. To do this, the first four moments (mean, standard deviation, skewness and kurtosis) of actual versus planned duration and cost (log) ratios are analyzed by project, phase of execution and activity type. Results suggest that, contrary to common wisdom, construction activities do not end late on average. Instead, the large variability in the activity duration is the major factor causing significant project delays and cost overruns. The values of average activity duration and cost variability gathered in this study will also serve as a reference for construction managers to improve future construction planning and project simulation studies with more realistic data.
- Architecture, Building and Civil Engineering