Quality management is supported by the quality management system, the system specifies a lot of responsibilities, steps, processes, methods, etc., but it is not possible to face the mask to the face, there are also some not written into the secondary items and temporary changes in the program, so it can only be said that the quality management system is a part of quality management, quality management is a little broader than the scope of the quality management system.
Your thesis, if you only write about what is in the quality management system, shows that your scope is not big, but, as a good thesis, it is not possible to write everything in it, otherwise, the breadth is enough, the depth is not enough. You have too much variety in your arguments and arguments, which will lead to a lack of argumentative content.
So, I think the teacher is giving you a range, not requiring which points must be written, and there should be no problem.