https://doi.org/10.24928/2026/0315
Schedule delay in construction delivery methods under extreme uncertainty
Junting Song1, Daniel Esmeral Jaramillo2, Yu-Peng Lu3, David Eskew4, Christopher Abandoh5, Tran Nguyen6, Pardis Pishdad7 & Qinghao Zeng8
1School of Building Construction College of Design, Georgia Institute of Technology, Atlanta, Georgia, [email protected]2School of Building Construction College of Design, Georgia Institute of Technology, Atlanta, Georgia, [email protected]
3School of Building Construction College of Design, Georgia Institute of Technology, Atlanta, Georgia, [email protected]
4School of Building Construction College of Design, Georgia Institute of Technology, Atlanta, Georgia, [email protected]
5School of Building Construction College of Design, Georgia Institute of Technology, Atlanta, Georgia, [email protected]
6Part-time Lecturer, School of Building Construction, College of Design, Georgia Institute of Technology, Atlanta, Georgia, [email protected]
7Professor, Graduate Program Director; Director, Smart Built Environment Eco-System (Smart Bees) Laboratory, School of Building Construction, College of Design, Georgia Institute of Technology, Atlanta, Georgia, [email protected]
8School of Building Construction, College of Design, Georgia Institute of Technology, Atlanta, Georgia, [email protected]
Abstract
Increasing global disruptions, such as pandemics, trade policy shifts, and supply chain shocks, have intensified uncertainty in construction project delivery. Yet much prior research has examined how project delivery method selection influences project outcomes under conventional conditions, with limited attention to performance under extreme uncertainty. This exploratory comparative study examines schedule delay performance across four delivery methods, Design–Bid–Build (DBB), Design–Build (DB), Construction Manager-at-Risk (CMAR), and Integrated Project Delivery (IPD), with the COVID-19 period (2020–2022) serving as an empirical case of extreme uncertainty. Using publicly verifiable multi-source project documentation, including Federal Emergency Management Agency (FEMA) disruption records, Engineering News-Record (ENR) reports, and project documentation, this study compiled a dataset of 17 non-residential construction projects using a self-defined, normalized Uncertainty Schedule Delay Index (USDI). Descriptively, within this dataset, more collaborative delivery methods, such as IPD and CMAR, tended to show lower schedule delays than DBB and DB. To contextualize these findings, practitioner insights were collected through interviews highlighting early engagement, proactive procurement, and effective team communication. Together, these findings contribute exploratory comparative evidence on delivery method performance and offer practical insights for schedule risk management under extreme uncertainty.
Keywords
Collaboration, integration, schedule delay, uncertainty, Integrated Project Delivery (IPD).
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Reference in APA 7th edition format:
Song, J., Jaramillo, D. E., Lu, Y., Eskew, D., Abandoh, C., Nguyen, T., Pishdad, P. & Zeng, Q.. (2026). Schedule delay in construction delivery methods under extreme uncertainty. In Hamzeh, F., Poshdar, M., & Garcia-Lopez,, N. P. (Eds.), Proceedings of the 34th Annual Conference of the International Group for Lean Construction (IGLC 34) (pp. 655–667). https://doi.org/10.24928/2026/0315
Shortened reference for use in IGLC papers:
Song, J., Jaramillo, D. E., Lu, Y., Eskew, D., Abandoh, C., Nguyen, T., Pishdad, P. & Zeng, Q.. (2026). Schedule delay in construction delivery methods under extreme uncertainty. IGLC34. https://doi.org/10.24928/2026/0315
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