Ask HN: How best to structure a "start-up" of 25 people

I'm in a software engineering class, and the class is being run like a start-up (theoretically). We have a customer, a summer camp that wants to move from a paper based sign-up for art classes to a more automated system.

Currently we have 4 people who volunteered to be managers, and about 20 other folks.

As a class we have to decide how to structure the teams. Since the product can be divided into 3 groups- teacher interface, student interface, and billing- the managers are considering dividing students into three groups.

However, to me this seems like a suck way to do it. I was wondering if any HNers have any ideas (or links) on how to structure a group of this size.

A 25 person startup is 22 people too many.

Actually the students would learn more if the class was broken down into 5 startups all competing for the customers work. This would give you 5 small tightly focused groups. Each would have to nominate a leader and or agree on a unified vision for their approach. Then fire the gun, BANG and get to work. Break out your roles, do yer thing, but most of all focus on that customer and learn about the problem.

The problem with one big class is that now you have to have 25 people agree on the vision/course of action, good luck, and you stir up the pot to get 4 folks or less to basically lead/do/all the work and or you ignore people that had good ideas but maybe not the best communication skills to bring/push those ideas to light.

Plus the customer suffers with just one vision. Why not produce 5 in a class, bounce around perspectives, ideals etc, and have people reflect on how their group performed- challenges, successes and weaknesses.

Sure the client sorta gets a taste of spec work startup style but the students can potentially learn more and feel like they have more skin in the game due to smaller groups.

The competitive edge makes it fun as well.