Time‐cost model for building projects in Nigeria

Abstract

The concept of project duration is important in assessing the success or viability of a construction project. A time‐cost relationship for construction projects in Nigeria has been developed based on Bromilow's time‐cost model. Cost data on 87 completed building projects executed within the period 1991–2000 were obtained. The data were subjected to regression analyses using double log and later the piecewise model with breakpoint. For the Nigerian situation, the Bromilow's time‐cost model was found to be T = 63C^0.262 with poor predictive abilities (R = 0.453, R² = 0.205). An improved model using piecewise model with good predictive abilities (R = 0.875, R² = 0.765) was found to be T = 118.563−0.401C (C ⩽ 408) or 603.427 + 0.610C (C>408). The model is shown to be useful in predicting construction project durations.

Keywords:

• Project management
• cost
• time
• cost modelling
• Nigeria

Acknowledgements

The authors are grateful to the four anonymous reviewers for their constructive comments which have helped to improve the quality of the manuscript. The partial financial support received from the University's Research Grants Committee of the Federal University of Technology, Akure is also acknowledged.