Your local network infrastructure includes cabling, data jacks, patch panels, patch cables, equipment cabinets, switches, and routers. An organized and labeled network infrastructure makes it easy to maintain and troubleshoot. No one likes to work on a “spaghetti network” where one false move can break something. Having your network documented gives you a handle on what you have and how it is put together. That makes my life easier and will cost you less in the bargain.