In his article “The Systems Engineering Mindset, Problem Solving and Critical Thinking,” James Lackey makes the case that the principles of Systems Engineering can and should be practiced by everyone. In this article (which is turning into a series) I’d like to expand on his point by taking a Systems Engineering tool and applying it to everyday troubleshooting: the Fishbone Diagram.
Pop quiz, hotshot: Your satellite has just lost communication with ground control: What do you do?
I’ll get back to that example in a minute, but let’s start with a more, ahem, down to earth example. Almost all of us have had the experience of trying to fire up the old PC, only to discover that nothing happens. Time to troubleshoot! You ask yourself the following questions:
- Is it plugged in?
- Is the power on in the house?
- Is it turning on, but the display isn’t working?
- Is it turning on, but the hard drive crashed?
A more rigorous way of approaching this troubleshooting example is to draw a diagram
In the drawing, I’ve categorized the various potential problems. For example, Plugged in and House Power fall into the Power category. I then add more “bones”
Ideally, each bone would have a likeliness associated with it. For example, you don’t hear any noise from the computer when you turn it on, so it’s unlikely to be a problem with the graphics. You’d also have a test associated with each bone: Check the plug is the test to see if it’s plugged in.
Back to the satellite example. The fishbone diagram contained 6 main bones and dozens of smaller bones. I won’t draw it here, but it was complicated.
That’s the real power of a fishbone diagram. For a simple troubleshooting issue like the computer, you don’t need a fishbone, but if you have a more complicated issue, it helps shape your thinking and provide a clear path towards the solution.