Over the last few decades, a number of mathematical models have been introduced for solving Multi-mode Resource Constrained Project Scheduling Problems (MRCPSPs). However the computational effort required in solving those models depends on the number of variables. In this paper, we attempt to reduce the number of variables required in representing MRCPSPs by formulating two new event-based models. A comparative study was conducted by solving standard benchmark instances using a common objective function for the developed as well as the existing mathematical models. The study provided interesting insights about the problem characteristics, model sizes, solution quality, and computational effort of these approaches.