Defining a mission
The mission is this institution's role inside the vision, not a sentence that could belong to anyone else.
A vision is the definite future an institution is willing to judge every small decision against.
A vision is not a horizon you admire and never reach. It is a definite future, concrete enough that an ordinary decision can be held up against it.
The test is blunt. Does this take us closer, or farther? If a sentence cannot answer that, it is not a vision. It is a mood. The point of writing it down is to have a boolean for the work, every day, not a paragraph for the wall.
This is why the vision comes before the mission. You cannot know what role an institution should play until you know which world it is trying to help bring about. That role can change. The mills can be sold. The boats can be burned. What those changes are for does not change with them. The mission moves. The vision is what it moves toward.
Call it the good place, not nowhere. A vision that cannot be built is an excuse to leave the present untouched. It can be a manifesto, a set of essays, or a single line. What it cannot be is private. It is the world this institution intends to inhabit with others, not a portrait of its own success.