Facility network provides a modeling method for common facilities such as municipal water network, transmission lines, gas pipelines, telecommunications networks, water system, etc. in our real world. All the networks' resources are flowing directionally, which can be modeled and analyzed with the facility network.

The facility network analysis is one of the common functions of network analysis. It mainly processes a variety of connectivity analyses and tracing analyses.

The facility network analysis must follow some rules to build the network models. It must have the flow direction, which is the flow direction of the substance. The network direction depends on the network topology, and the locations of the source and sink.