In agreeance with all the above responses, the project manager has a lot of important responsibilities. I believe, however, that all these responsibilities fall under the single biggest challenge a PM faces which is effective communication among all the departments working together on the project. The need for this transparency is critical to the success of the project because it keeps everyone informed and accountable about the current goals, progress, issues, and deadlines along with holding individuals responsible for work they need to get done. However the PM decides to organize the information structure of the company, (whether it be though frequent meetings, email, phone, etc.) it is imperative that it accurately portrays important aspects of the project while promoting an open and effective lines of communication for essential feedback. It is only once this transparency is achieved amongst all the departments that the project can progress as quickly, efficiently, and effectively as possible. If effective communication is not achieved, it will be very hard for the PM to organize an effective work force and meet all required deadlines.