Is there an industry standard?

I am working as a student intern under the State of Pennsylvania. One of my tasks was to figure out what the industry standard, or the best practice in terms of setting up a corporate network. We want to know in terms of should you place an entirefloor on one switch, split up the wings on different switches, keep departments together, or what the best practice is when placing computers on switches. It is my job to do research on this topic and reconfigure the network according to the industry standard, or the road most traveled. Our building has three floors with two wings on each floor. Each wing holds a different department. My concern is if a switch goes down, do we want a whole floor going down, a wing, a department, or do we want the outages scattered throughout the building. I hope you can help me or lead me in the right direction so I can find that information.