Although “powerful” is a subjective term, with regard to completing a project successfully or not, the project manager is the most powerful stakeholder involved in a project. There are a variety of opinions concerning this, but fundamentally it is the project manager’s skill set and role as stakeholder that drive the success of the project, regardless of other stakeholders and negative external factors.
A project manager is considered a stakeholder according to the Project Management Institute’s definition. Although not the only stakeholder, the project manager personally holds the power to direct the project and its resources to a successful outcome for all of the other stakeholders. While some other key stakeholders may be able to influence the project in negative ways, a good project manager has the tools and techniques to mitigate any stakeholder wrongdoing (negligent or not) through communication processes and interpersonal skills to keep the project on track. This implies that the project manager’s ability to effectively use the tools and techniques provided in the PMBOK play an important role in the project’s outcome if the they are given the appropriate respected authority.
Even if a project was performed in a perfect environment (one where scope, budget, time, and quality constraints were easily met with helpful knowledgeable stakeholders) the project manager can cause the project to fail by poorly managing the project resources or stakeholder input. This further leads to the idea that the project manager and his or her skills are an important factor in project success despite having an optimal project environment.
Negative influences can surround a project but a project manager has the tools and techniques needed to deal with many issues. Ultimately, the success of a project is dependent on the skills and abilities of the project manager and this makes them the most powerful stakeholder involved in the project.