[pencilcheck]

I would say a incompetent PM wouldn't be able to make their own deadlines but to only comply deadline set by their superior who of course has no intention or knowledge on how the system actually works and the time it takes to accomplish them. A good PM would be able to fight back and make a much better deadline that both engineer, sales, marketing, design and business all would be happy about. In my mind, a great PM pushes tech to meet new business goals and pull business to be aware of technical pitfalls. A great PM is in control of all sides of the project and able to pull them together without being expert in any of the fields.