The student team brings to the project a combined knowledge base and skill set that spans a significant portion of the knowledge and skills needed to do the project. However, when the student team has little of the prerequisite knowledge and skills to do the project, the project starts off with a significant penalty. The selected project is a good match to the expertise of the project advisor. Also, it is a plus for the students when the advisor has a substantive vested interest in the successful outcome of the project, e.g. the design project is supporting the advisor's research or it will be used by the advisor in one of his or her courses.
Students are highly motivated, self starting and persistent.