This notion leads to Guerrilla Mantra 2.4:
A performance model is more like a map of a metro rail system than a scaled replica of the metro railway.
Elsewhere in my classes, I compare computer performance management with other aspects of computer system management. There, I like to say that the requirements for doing performance management are disproportionately greater than the requirements for other aspects of system management, e.g., security, and software distribution. Many of the latter management activities can be satisfied with COTS software solutions. Despite what you may read in trade rags, there are no shrink-wrap solutions that cover all the complex aspects of performance management. Companies need to invest in human infrastructure—not a popular message these days. I sum all this up in Guerrilla Mantra 1.8:
If computer system management is represented as the human body, i.e., everything in geometric proportion, then the disproportionate skills required to do proper performance management are more like a homunculus (lower left in the above collage).
In a strange quirk of fate, someone recently tweeted the work of Dutch graphic designer Samantha Loman, where she has represented the various subsystems of human body as a metro map, similar to the London Tube (right-hand side of the above collage). The juxtaposition was too good to pass up, so I contacted her and she has given me permission to use her human metro map in my classes and possibly in the 2nd edition of my Guerrilla Capacity Planning book (if I ever get around to it).
BTW: Is Sam's illustration another definition of "metro-sexual"? :)