 <p>When compiling project A maven will first try to look-up the project dependencies B, C, D, E. He will look at the local repository (usually a hidden directory .m2 under user’s home directory) or a remote repository. </p> <p>In your case B, C, D, E are your local projects and not third-party so executing maven install for B, C, D, E. will compile them and copy them to local repository. When you do maven install on A they will not be compiled again.</p>