Based on the previous post, if you have an SOA project, you could have multiple project files as part of your solution. For example, if I have a Class Library, a Web Site Project and a couple of Web Service Projects, I will potentially have 2 deployment projects for each Web Project and deployment for the Class Library as well as a testing project for each. To tame this solution, you can use a solution folder to contain and hide the solution's complexity. Right click the solution and add the solution folder. Then drag projects into the solution folder. This organization is strictly logical and the solution's physical layout stays the same on disk.