I have one solution with 3 related projects: 1) a Windows console app that reads data and stores it to a mssql DB, 2) WCF service that will retrieve from mssql data, 3) website that will read from the WCF. There could be other projects in the future. The first two projects (and any related future projects) use a Sqlhelper class. Should I create a separate project for it? The most ideal one would be a class library, but I don't know if a WCF invoking a DLL is correct. Any help is appreciated. Thanks.