Viva prep comes after you’ve finished and submitted your thesis. Before submission your focus has to be on finishing your research and your thesis, with some attention reserved for life and your future beyond the PhD.
That’s not to say there aren’t useful viva-related things to do before submission. but they’re all small. They don’t really count as prep:
- Read the regulations. Get a sense of the process at your university and the outcomes and timescales involved.
- Plan your prep. You don’t need to get ready, but you can prepare to get ready! Sketch out how you will do it when the time comes.
- Discuss your examiners with your supervisor. Who are they? Why are they good choices? Can you make suggestions?
The last task is bigger but still a very small task compared to everything else you’ll do to get to submission. Suggest examiners if your supervisor asks, discuss why their choices are good ones for your viva if they are already set. You don’t get to formally choose examiners, but you can be sure of who they are and why they are good for you.
And apart from these three tasks: finish your research, finish your thesis and plan for life after the PhD.