I wouldn’t necessarily say they are the most important parts of the entire project, but I would agree that these are very important aspects of the executing phase of a project. Having poor communication, selecting the wrong suppliers, or not maintaining a good relationship with your suppliers are all things that can definitely derail or sink a project. However, other things that occur during the initiating phase and planning phase can derail a project just as much, therefore I would not conclude that these parts of the executing process are the most important parts of the project.