Hello, can you please help me come up with a dissertation topic concerning organisational culture, I want to investigate how it works, its pros and cons, using a business as a case study.

What do YOU think ?

Dissertation for a PhD, Masters? What are your interests? You must have some by now or you wouldn't have gone this far.
I'm not sure if these fall under organisation:
- Profit sharing, or employee owned.
- Many small hi-tech companies have no set work or time off hours.
- Companies owned by family for many generations
- Hierarchies: Mark Zuckerburg of Facebook is famous for not having an office; he shares the same open space everyone does.
- Some companies promote on merit and some on seniority.

A company near me in the US is King Arthur Flour, in business since 1790 (very old by American standards). It has 300 employees and has been 'employee owned' since 1996. I don't know the details.
I remember an ad for an Italian bank in the Wall Street Journal once that caught my eye because it said 'In business since 1492.'