A grey mathematical programming model to time-cost trade-offs in project management under uncertainty

Time and cost are two salient elements indicative of success in project management. This importance obliges the project managers to seek for the best feasible amalgamation of time and cost regarding project's activities. This condition engenders a trade-off problem in terms of creating a required balance between time and cost considerations to execute all activities in a project efficiently. Such problem relates to time and cost trade-offs issue. Time and cost trade-offs model is based on estimated values of time and cost required for a given activity to be complete in a normal or crashed form. Current models of time and cost trade-offs have made use of crisp values for these estimations. In this paper, we extend a model for time and cost trade-offs based on grey numbers to deal with the uncertain nature of time and cost estimation. The proposed method has also been applied in an example and interpretations pertaining to offered solutions have been examined.