Once you have a ‘why’ to your business, then what?
How do you craft a vision statement? Is it different from a mission statement or an ethical code etc.?

Collins and Porras have a simple and meaningful model. Rather than spend valuable time understanding the subtleties of mission statement versus ‘our purpose’ etc., consider the following rationale.

A long lasting vision statement has 2 components:
a) a core ideology (made up of core values and a core purpose) and
b) an envisioned future (made of a very high goals and a vivid picture)

And what about the values versus purpose etc.? These are actually already in your business.
The values are simply the things that define you anyway.

They are intrinsic and must be real for anyone to believe them. For Nordstrom’s it is service, P&G is product excellence, Walt Disney’s is happiness and wholesomeness. Your business will have these even if they do not confer a competitive advantage.

The latter is your purpose.
And this is where it is easy to be descriptive about what you do. This is the ‘why’ from the first exercise. It should reflect not only what you do but why you do it. It is not the specific strategies of how you do what you do. Merck’s is to preserve and improve human life. 3M’s is to solve unsolved problems innovatively.