| A | B |
| Input | enters the system to start the process |
| Process | Procedure taken to achieve the results |
| Output | Results of a system that can be measured |
| Feedback | Part of the input returns to the output |
| Open System | New input must continually entered into the system |
| Closed System | The output returns to the input. Nothing new is added |
| Hub and Spoke | Contains a central hub, remote nodes, and spokes for communication |
| System | Individual parts working together to achieve a result |