DATAL is a newly founded company that provides data analytics solutions. It has 4 departments (D1, D2, D3 and D4) located on 2 floors of a same building. Each department will have its own LAN. The LAN for D1 and D4 will connect 6 clients, 3 servers and 1 network printers whereas the LAN for D2 and D3 will each connect 10 clients, 4 servers and 2 network printers. All clients (NICs included), servers (NICs included) and network printers have already been bought and do not need to be considered in this exercise.

CLEARLY explain (i) what "structured design" means, (ii) its major benefit(s) and (iii) how it applies to DATAL's network (6 lines MAX).