A network plan lists different subnets, user groups, and different servers. Essentially is puts all your resources on the network, and shows how the parts of your network are connected. Keeping your plan updated will also help you troubleshoot problems more quickly when they arise.

A network plan helps your static routing by eliminating potential bottlenecks, and helping troubleshoot any routing problems that come up. Also you can use it to plan for the future and act on any changes to your needs or resources more quickly.