A servlet-based system looks something like the diagram in Figure 4.1. Client workstations, using Web browsers, access our server over the Internet. Our server serves pages that contain servlet URLs. Those servlets execute on the server and generate HTML that is sent along with the pages. The servlets draw their data from and manipulate a Microsoft Access database.
The simple model in Figure 4.1 is sufficient to be able to generate estimates of the stories. We can see where those stories fit and judge how much effort they will require.
Figure 4.1 System architecture