Abstract-This paper presents methods solving MS-RCPSP as a main task-resource-time assignment optimization problem. In the paper there are presented four variants of Evolutionary Algorithm applied to MS-RCPSP problem: concerning prioritization the tasks (or resources), combined task-resources prioritizing approach and co-evolution based approach that effectively solves problem dividing it to two subproblems. All approaches are examined using benchmark MS-RCPSP iMOPSE dataset and results show that the problem decomposition is effective. All experiments are described, statistically verified and summarized. Conclusions and promising areas of future work are presented.