Multi-project management is very complex task, which often involves the integration of varieties of resources and schedules. In recent years, many researchers have proposed many techniques for project scheduling problems. However, due to its complexity, it is difficult to find out the best scheduling scheme using heuristics or non-traditional techniques. In this paper, the aim is to find out the high-performance algorithms to solve combination optimisation problems. Related comparative analysis of swarm intelligence and heuristic priority rules for scheduling a multi-project environment with an objective to minimise the makespan of the projects is explored. Firstly, the multi-mode resource constrained multi-project scheduling problem (MRCMPSP) and its conceptual model are proposed. Then, swarm intelligence and heuristic priority rules to the MRCMPSP problem are discussed. Thirdly, the simulation experiments are given in order to test the different searching abilities for various scale scheduling problems using these two methods. Finally, some interesting insights are also illustrated through numerical examples.