The answer to this depends on what you mean by a really detailed outline. If you mean that you have a well-worked out argument structure, this is wonderful. If you mean that, for a particular section, you know exactly what steps you need to take, say, for an experiment, then that's also useful. If you mean a plan of action where each part is directly aimed at achieving your objective and this relationship is evident, then this too is of great help. And, at a later stage, a comprehensive yet still flexible outline of what is going to be included in each chapter, and which comes out of the structure of your argument as a whole, is of great help in that it allows you to foreground just one section, that is a do-able bit, and write that, knowing where it fits. However, we see some students in the earlier stages of doing a PhD who produce, often with a flourish, a very detailed outline, down to every last sub-sub-section: Perhaps there is not much wrong with this as a Table of Contents. But as an outline of what you're going to do, it serves no purpose. Students who produce such an outline could still finish up with a brilliant thesis, especially if all the links and the reasoning are in the head. However, unfortunately, such an outline doesn't tell anyone what has led to this proposed research, why it's important and how the various parts indicated in the outline are related. It is not a document someone can work from or offer you useful feedback on. We usually find that students who produce something like this as a starting point have the concept of their thesis project as a formulaic set of necessary steps. Sometimes they have adopted an outline from a thesis done previously in their department. At this early stage students are understandably often so caught up in the content, they do not see the necessity to have an overall idea of where the study is going. Often a very detailed outline of the table-of-contents type can delude you into thinking you have accomplished something. It can, to the contrary, actually imprison you and restrict the room for creative thinking. It blocks the necessary questioning processes: revisiting the topic, reassessing the direction your thesis is taking, and seeing how you would structure your argument.

	Deciding on your structure.
	Seeing the plot emerge.
	Developing a picture of the thesis as a whole.
	Preparing an outline.
	Achieving unity in your thesis.