The project manager is the individual responsible for delivering the project and leads the project team. Big projects are difficult , so sometimes organizations might be tempted to have more people involved. A single, dedicated project manager can run the project smoothly because even when there are a lot of people involved at a high level, there needs to be a single person who is empowered to make the final decision. If there are multiple project manager on a project, that would increases the chances of conflicts of interest , confusion and problems regarding responsibilities and accountability but if the roles and responsibilities of each project manager are well defined in the project plan then project can progress well , on the project where the roles and responsibilities of each project manager are not well defined in the project plan, those projects rarely progress well. Communication also play an important role in project having multiple project managers.