Human System in Project Management

I always emphasize that Leadership is the most important role played by the Project Manager like many other authors do. And i always looked at the importance of "People" and "Tools and Techniques" aspects of Project Management. PMBOK teaches us the "Tools and Techniques" than can be used in managing projects but cannot teach us how to manage people involved in projects. Whether it is project management or sales management everything that is linked with human element can be a human subsystem. To have an understanding of this human subsystem project managers need to have knowledge on communications, semantics, psychology,leadership and so on. Project Managers must be able to put themselves into this subsystem so that all the memebers of the project team are committed and loyal in acheiving the project objectives. This requires good motivation skills and a crafty management style and will decide the success or failure in projects.