TOPSIS has been in use for more than 20 years in many fields. However, few researches have studied its defect of rank reversal. This paper, by studying the fundamental cause for the rank reversal problem in TOPSIS, put forward an improvement on TOPSIS based on the decision maker’s subjective preferences, which can, proved by a numerical example, overcome the rank reversal problem and lead to more scientific decision result that is in more agreement with the decision makers’ subjective intensions.

This paper introduces a new practical scheduling problem called the resource-constrained project scheduling problem under multiple time constraints, which involves a duration constraint of activity, temporal constraint, and resource calendar constraint. The duration constraint of the activity exists widely in real-life projects, and it is first proposed as a resource-constrained project scheduling problem in this paper. We prove the defects of the traditional temporal constraint and improve it. The new problem combines three types of time constraints for the first time, which makes it closer to the actual scheduling problem. We developed a constraint programming optimization model for the new problem and used the IBM ILOG CPLEX-CP version 12.9.0 optimizer to solve it. Computational experiments are carried out to show that the CP optimizer is fast and provides a near-optimum solution to the new problem for projects with hundreds of activities within minutes compared to other metaheuristic methods. The results reported in this paper can be used as a benchmark for other researchers to compare and improve. The new problem contributes to developing a practical decision support system for resolving real-life constraints in projects.