The most prevalent and one of the most difficult things you can face during a project is people. Getting the correct people, getting them to work together, getting them to perform together. You also have to take into account the scope of the project. You want to have defined, measurable goals and a timetable, so that they cannot be left to interpretation and there is a definite end point to the project. Resources, especially a budget for the project, can account for a lot of time in planning the project. Possibly the one thing that is MOST overlooked is the overview AFTER the project is finished. This is also referred to as a Start, Stop, Continue. What worked, or didn’t work? What should you keep doing, or what do you need to start doing to ensure success in the next project? These are just a few difficulties that you will face when carrying out a project. But this is a good start with some of the MAJOR difficulties. I hope this helps.