Quite an interesting topic. First of all, the notion of quality needs to refer to some point of view. The notion of quality that management and administrations have might prove quite different from that of students or even faculty. And this not to mention workers or political institutions...
Higher education includes a lot of things and quite many people. So any attempt to explore quality in this sector needs to first establish from what point of view. It can also attempt to explore from all points, if the objective is to understand the subjective points of view from all the actors that constitute higher education. Several works exist on this matter and they have showed how students, faculty, workers and management attribute different value to specific aspects. Students might not be interested in the financial state of the university if its doing well enough for them not to be exposed to worries about sustainability, but management might think about it constantly. Faculty might be more worried about working conditions that students. And quality and diversity of courses might not say anything to the workers.
It is also important to understand the political reality behind higher education. Private universities work differently than public ones. And even public institutions tend to work differently from country to country. Such backgrounds greatly affect how the sector works (career chances, work expectations, etc).