an effective method for simultaneously considering time-cost trade-off and constraint resource scheduling using nonlinear integer framework

critical path method (cpm) is one of the most popular techniques used by construction practitioners for construction project scheduling since the 1950s. despite its popularity, cpm has a major shortcoming, as it is schedule based on two impractical acceptance that the project deadline is not bounded and that resources are unlimited. the analytical competency and computing capability of cpm thus need to be enhanced by applying some additional techniques like time-cost trade-off (tct) and constraint resource scheduling (crs) separately after the initial schedule is determined. therefore, this paper is focusing on an effective method for considering simultaneously tct and crs using a nonlinear integer framework, taking help of microsoft project software (msp) and microsoft excel solver. through this method, first, a start delay technique is applied to the baseline schedule to level out the resource over allocation and then the project network diagram is modified according to the resource-leveled schedule. secondly, a time-cost optimization is used over the resource-leveled schedule network diagram, using ms excel solver to get the optimum duration associated with the minimum total cost of the project satisfying resource constraint. the proposed framework using overtime for activity expedition, and required less time to generate the final solution compare to the available methods considering tct+crs simultaneously.