Construction time-cost trade-off optimization system

Construction planners face the decisions of selecting appropriate resources, including crew sizes, equipment, methods, and technologies, to perform the tasks of a construction project. In general, there is a trade-off between time and cost - the less expensive the resources, the longer it takes. Using CPM techniques, the overall project cost can be reduced by using less expensive resources for non-critical activities without impacting the duration. Furthermore, planners usually need to adjust the selection of resources in order to shorten or lengthen the project duration. Finding the optimal decisions is difficult and time-consuming, considering the numbers of permutations involved. For example, a CPM network with only 8 activities, each with two options, will have 256 (2⁸) alternatives. Exhaustive enumeration is not economically feasible even with very fast computers. This paper presents a new algorithm using linear and integer programming to efficiently obtain optimal resource selections that balance time and cost for a construction project.