Schedule Overruns in Vertical Construction Projects: A Review of Delay Factors and Mitigation Strategies

Schedule overruns remain a persistent challenge in vertical construction, driving up costs and delaying operational delivery across diverse project contexts. Hence, this review synthesizes literature on schedule overruns in vertical construction, examining reported delay factors, project consequences, and mitigation approaches, with particular attention to Philippine evidence. A thematic narrative synthesis organizes the cited studies by project and regional context rather than pooling unlike rankings or percentages. Philippine evidence includes a vertical-construction study in Pampanga that reports the relevance of material and labor price changes and tax and exchange-rate fluctuations; studies in Cebu and Mati describe management, workforce, change-order, and financial issues in their respective project settings. Across the wider literature, recurring concerns include contractor cash flow, site coordination, design and approval processes, and material availability. Reported effects include extended project costs and operational disruption, although these outcomes vary by project type and study method. The evidence supports context-specific responses, including realistic procurement and cash-flow planning, coordinated scheduling, and constraint-focused production planning. Digital tools such as 4D building information modeling and lean methods may support these responses, but their effectiveness should be assessed against project-specific data. The reviewed studies do not justify a universal ranking of causes across countries or sectors.