2.2.1 A first diagram
For example, think about the inputs to the running of a commuter rail operation and the outputs from it. The diagram might look like the one in Figure 10.
The advantage of portraying inputs and outputs in this way are as follows:
The portrayal will show the inputs and the outputs in a way that emphasises the flow of inputs into the operation and the subsequent flow of outputs from it. The use of the arrows will establish this sense of movement.
At the same time, the diagram will provide the benefits of the two matching lists, the inputs and the outputs. You will gain a sense of the transformation of the inputs into outputs.