27.1. Communication and Size

If you're the only person on a project, the only communication path is between you and the customer, unless you count the path across your corpus callosum, the path that connects the left side of your brain to the right. As the number of people on a project increases, the number of communication paths increases, too. The number doesn't increase additively as the number of people increases. It increases multiplicatively, proportionally to the square of the number of people, as illustrated in Figure 27-1.

Figure 27-1. The number of communication paths increases proportionate to the square of the number of people on the team

As you can see, a two-person project has only one path of communication. A five-person project has 10 paths. A ten-person project has 45 paths, assuming that every person talks to every other person. The 10 percent of projects that have 50 or more programmers have at least 1,200 potential paths. The more communication paths you have, the more time you spend communicating and the more opportunities are created for communication mistakes. Larger-size projects demand organizational techniques that streamline communication or limit it in a sensible way.

The typical approach taken to streamlining communication is to formalize it in documents. Instead of having 50 people talk to each other in every conceivable combination, 50 people read and write documents. Some are text documents; some are graphic. Some are printed on paper; others are kept in electronic form.