One of the great ironies of project management is that project managers spend considerable time communicating. Yet, few can do so very well.
If project managers want to lead, not just manage, they must acquire and exercise good communication skills. This is a prime activity of an effective leader who expects to successfully complete a project involving the participation of other people. As John Gardner notes, two-way communication is an important ingredient in establishing and sustaining the relationship between leaders and followers. 
Leaders must not only establish good communication, but also sustain it. In People Skills, Robert Bolton agrees and acknowledges the importance of open , clear communication and says that when it deteriorates, it has negative consequences on the leader-followers. 
The job is not, however, getting done effectively. As Hersey and Blanchard observe, despite the fact that managers in general are doing so much, there seems to be so much room for improvement at the same time.  A report by the Canadian Manufacturers and Exporters agrees, observing that improvement is needed in three areas: problem solving, communication, and teamwork. 
The importance of communication is substantiated in other research as well. For example, a survey of managers by Training magazine with The Center for Creative Leadership found that communication was the second most important leadership challenge.  Training and Development magazine identified ten skills that managers need to be a success, at least from a Human Resource manager's perspective. All contributed to success to various degrees. The skills were interpersonal, listening, persuasion and motivation, presentation, small group communication, advising , interviewing, conflict management, writing, and reading. 
At first glance it would appear that communication is important only to senior executives. Nothing could be more misleading. It also has a great level of importance for leading projects. In Project Management , Harold Kerzner observes that communication on projects is critical. 
My experience supports this assertion. It is one failure or shortcoming common to projects in trouble. If project managers do not exercise good communication on an individual and group basis, their projects will have a lesser chance of success. If they do succeed, then they will do so with great effort. Hence, the responsibility for establishing and maintaining effective communication rests directly with project managers.
Project managers must make a conscientious effort to encourage and sustain communication among all stakeholders. It is the responsibility of the project manager to lay the groundwork and manage it throughout his or her project. 
 John W. Gardner, On Leadership , The Free Press, New York, 1990, p. 26.
 Robert Bolton, People Skills , Touchstone, New York, 1986, p. 6.
 Paul Hersey and Kenneth H. Blanchard, Management of Organizational Behavior , 6th ed., Prentice Hall, Englewood Cliffs, NJ, 1993, p. 327.
 2002 Research Report from Canadian Manufacturers and Exporters, PM Network , p. 10, March 2003.
 Joel Schettler, Leadership in corporate America, Training , p. 70, September 2002.
 Top ten, Training and Development , p. 10, February 1999.
 Harold Kerzner, Project Management , Van Nostrand Reinhold, New York, 1995, p. 275.
 Joan Knutson, You owe your project players a common infrastructure - Part 1, PM Network , p. 21, November 1999.