27.2. Range of Project Sizes

Is the size of the project you're working on typical? The wide range of project sizes means that you can't consider any single size to be typical. One way of thinking about project size is to think about the size of a project team. Here's a crude estimate of the percentages of all projects that are done by teams of various sizes:

Team Size	Approximate Percentage of Projects
1 3	25%
4 10	30%
11 25	20%
26 50	15%
50+	10%
Source: Adapted from "A Survey of Software Engineering Practice: Tools, Methods, and Results" (Beck and Perkins 1983), Agile Software Development Ecosystems (Highsmith 2002), and Balancing Agility and Discipline (Boehm and Turner 2003).

One aspect of project size data that might not be immediately apparent is the difference between the percentages of projects of various sizes and the number of programmers who work on projects of each size. Because larger projects use more programmers on each project than do small ones, they employ a large percentage of all programmers. Here's a rough estimate of the percentage of all programmers who work on projects of various sizes:

Team Size	Approximate Percentage of Programmers
1 3	5%
4 10	10%
11 25	15%
26 50	20%
50+	50%
Source: Derived from data in "A Survey of Software Engineering Practice: Tools, Methods, and Results" (Beck and Perkins 1983), Agile Software Development Ecosystems (Highsmith 2002), and Balancing Agility and Discipline (Boehm and Turner 2003).