This week marked the last formal panel session, and thus this is my final entry into this portfolio. In this entry I want talk about something that has come up again and again through my portfolio entries, the human component of systems. At the surface level it seems a trivially obvious statement to say that systems engineering is a people driven affair; systems are built by people to service the needs of people. I want to go deeper than this though. During the big picture panel Geoff Patch of CEA was asked whether his radar software development team, pays much attention to interfacing with the user of the system. He responded that no, they didn’t, because their system simply connected into a larger system, responsible for displaying data to the user.
This is ostensibly true, his system doesn’t directly display information to the user, but it still interfaces with the user. No, it isn’t responsible for drawing the lines on the screen, but the information it provides guides a users decision, it influences how the user reacts to a situation. To take a bold step and generalise this, any part of a system always has some interface to some user. The link might be tenuous, but it’s there. Looking at writing code, the code itself interfaces with the user by the manner in which it is written; the comments, the names of variables. The user the code interfaces with, i.e. those who write and maintain it, is different from the user the program interfaces with, but they still interface with a user.
These interfaces drive so many of the adjunct concerns with systems engineering. Sustainability is focused on ensuring that the systems interface with future users is a non-destructive one. Ensuring a systems safety requires safeguarding the user interfaces. It requires understanding where those interfaces are and what risks are potentially associated with them. Some interfaces and their risks are more obvious than others, a planes interface to it’s passengers is much more direct than a nuclear power plants interface with future inhabitants of earth, but they must both be considered carefully.
These interfaces have constraints, they have limits imposed implicitly or explicitly by the users on the other side. Abstraction, for example, is a response to a constraint placed on this interface by human attention spectrum limitations. Communication between professionals of differing domains, as well as between technical and lay people, must accommodate the knowledge and experience restrictions these communication interfaces present. Exploring and better understanding the user interface our road system presents, has led to radical rethinks about how we can signpost those roads to better communicate across that interface to users.
The consideration of this interface and how the system, or component of the system, interacts with it does not except us from dealing with the cardinal portion of the system. Geoff’s radar must still detect objects in the sky, but to say that this system or section of a system, is devoid of a user interface is to miss the bigger picture.