This is how an exhibit gets built.
First, someone comes up with an idea. Then a team gets assembled, consisting of people who know the content, other people who know how to build exhibits, other people who just know about a lot about exhibits. An advisory board who is also familiar with the topic will be organized.
Then a lot of ideas get thrown around: what topics do we want to include? what do we want visitors to learn? what kinds of interactives should we have? how do we make it maintainable? how do we make it safe, and fairly indestructable? what do we want it to look like? what do we want the text to say? what colors do we want?
Eventually there are drawings and sketches and a model or prototype gets built, and we ask visitors a lot of questions. Then we go back and change things and try it again.
The whole process takes many months or even years, and it looks a lot like this: