The title of your dissertation should be easily reformulated into a question. Unfortunately, it is not customary to name a dissertation in the form of a question, but in your head you should have an interrogative sentence. You must understand exactly what you want to know and tell your readers.
When there is a question, it becomes clear what parts of it need to be divided – and these are the chapters of your dissertation. It turns out a system of questions – and this is the structure of your work.
This whole structure should be in the head from the very beginning. You can’t think that you will first learn something, and then develop a structure. As long as you have no questions, you are working with dead material: if you do not ask him anything, then he will not tell you anything.
Questions (and accordingly the contents of the chapters) are clarified and changed. If the original plan has not changed, then this is a little suspicious. This means that, probably, you did not study or think about it, but customized the material to existing questions and, most likely, answers. The original structure is being revised. But it is the original structure that is the direction of your movement. In some situations, you may even realize that you are at a standstill.
Remember that with a wrong work plan you can write a good job, but without a plan you can’t. The sooner you arrange the structure, the more likely you are to do the job well and not be traumatic for yourself.
Try to search for some dissertation examples, there are many sites like bibliothequer.com where you can find samples on any topic you need.
The topic should be visible and feasible. Do not wave and do not set super-global tasks.
I advise everyone to download and read Umberto Eco’s “How to Write a Thesis”. Umberto Eco says it cannot be too small or too narrow a topic. You can write a diploma on how marlboro cigarettes are sold in the nearest stall. But you should know everything about these sales. Too global a task takes you aside. It is better to expand the theme later than to wave to something that does not have enough time.
It is very useful to find optics, thanks to which you can reflect your professional activity with the help of analytical procedures and research questions. This is one of the possible heuristic tricks. Personal experience has the virtue that it is your own and not falsified. There is an expert on any topic who knows more. But you know best about your own experience.