Analysis of Cost and Time Overruns for Major Public Building Construction Projects in Dire Dawa City, Ethiopia

Cost and time overruns are the critical challenges for construction projects. The consequences can extend beyond just monetary losses, causing project delays and even project cancellation, with repercussions for various stakeholders potentially impacting the broader economy. The study aims to analyse quantitatively the cost and time overruns in public building projects in Dire Dawa city over the past 17 years. Long year’s quantitative cost and duration data for 99 public building projects were collected from different documents including contractual agreement, schedules, and financial records available from clients, contractors, and consultants. The data were analysed using descriptive statistics, Mann Kendall trend analysis, and Sen Slope estimation method. The findings revealed that over the period 2008 -2024, about 45.5 % of projects experienced both cost and time overruns, 12.2% experienced only cost overruns, and 32.2% experienced only time overruns. About 90% of the major public projects have experienced either cost or time overruns in the study area over the period. The remaining 10 % of projects were completed ahead of schedule and at lower cost than the plan. As to the extent of overruns, on average, projects exceeded their budgets by 20.7%. Around 50% of the projects experienced cost overruns of 16.5% or less. Similarly, projects delayed from planned schedule by an average of 229.1%. Around half of the projects experienced time overruns of 267% or less. The trend analysis revealed the percentage change in time over runs have showed no statistically significantly trend in the period (2008–2024). However, that percentage change in cost over runs have showed statistically significantly increasing trend in the period at a rate of 200% per year. It is clear that the prevalence and magnitude of time and cost overruns are generally significant and the temporal patterns of change in overruns are generally negative. It can be concluded that public project management efficiency with regard to cost and time management has not only been generally poor but also remained at unimproved for duration and either declining or unimproved for cost over the different periods despite efforts being put in to place in the industry. Therefore, it is required to identify site specific interventions in the planning, design, and implementation phases and implement the interventions to ensure more efficient public project management.