Can we consider organizational development part of the company strategy or it is a tool to achieve the strategy?

OD is part of the building blocks of a strategy to achieve company objectives.   Other important strategies is buy-in into the vision and mission of the organisation and to develop a set of values which are equally important.   Part of OD Strategy is to develop a learning culture, this in a way is also a strategy for attracting quality staff and retaining staff.   Most organisations fail because they don't pay heed to the importance of developing staff through learning programs, skills development and improved company processes.   the ability of organisations to adapt to the changing environment is critical to their long term success.   

In my point of view it's depending on the company's culture

In nowdays, I believe in many cases it's hard to dissociate them , organizational devellopment is at the same time

a part of the company strategy and a tool to achieve the strategy  

To make organizational development company strategy always plays the vital role along with the HR strategy and HRM policy-regulations. Through the development we can find out the lacking and advancement of a company and that can open the door for new light of more potential strategy for more development.