A Customer base data flow diagram is the most effective method for understanding and communicating these relationships internally. Explaining connections between many nodes in a network is difficult when describing how the Customer base data flow diagram flows. It is not easy to talk about or write about your entire local subway network, just as it is to listen to or read about. Your data flow diagram has a lot of moving parts. It takes some planning and a list to demonstrate the complexities of how it all comes together. We mean teams that can face difficult challenges head-on by effective customer data management.