Time-cost trade-off resource-constrained project scheduling problem with stochastic duration and time crashing

Abstract

In this paper, time crashing is implemented to solve the limitation of buffer insertion when consider the high variability of activities and resources in resource constrained project scheduling problem (RCPSP). The activity duration and resource are considered to be beta and exponential distributed, respectively. To settle the discrete time-cost trade off problem, a nonlinear combinatorial optimisation model is developed to pursuing the time, cost and robustness of the project. Six improvement principles are proposed and three balance points are discovered according to the different situations in the time-cost trade-off process, in which the earliness bonus, tardiness penalty, instability cost and time crashing cost are involved. To minimise total budget of the project, tabu search and starting time criticality heuristic is designed as the solution method. Finally, a numerical example is presented to highlight the efficiency of proposed model and solution method.