I am designing an n-tier Windows application by using .NET Framework 4, VS2010, and SQL Server 2008. The application will replace an existing client/server application. The existing application was created by using Microsoft Visual Basic 6.0 and consists
of a series of COM components that access a SQL Server database. I plan to move the existing COM components into a WCF tier.
I ensure that the COM components can be replaced without impacting the existing user interface (UI) tier. I also need to ensure that the COM components can be replaced separately.
I believe the way to do this is create a common assembly of the new application interface with the COM components. Should this be done on the
UI tier or the WCF tier?