Review of Time-Cost Optimization Techniques in Construction Project Management

Time and cost are two major factors to be considered in the construction project management. In general, there is a tradeoff between time and cost to complete each activity of a project. The relationship between time and cost can be presented by continuous function or discrete function. The choice of function is dependent upon the characteristics of the construction activity. The concurrent optimization of time and cost so as to maximize profit leads to the development of time-cost optimization (TCO) concept. Existing techniques for TCO including heuristic methods, mathematical programming models, and artificial intelligence techniques are reviewed in the paper. With continuous time-cost function, the TCO can be effectively performed by genetic algorithm (GA); whereas with discrete time-cost function, the TCO can be performed by ant colony optimization (ACO). Beneficial implications of TCO on the general construction planning are discussed with particular attention paid to the procurement of sub-contracts and critical materials, as well as human resource scheduling. Finally, remarks on the positive contributions of TCO in the construction industry are made.