If only software development was that simple

Last Christmas my father made a cool house out of card paper. As promised, here's the schematics I've reversed-engineered.

Now this is quite disturbing: I wrote a simple document most people can read and comprehend describing how to build the house. If people get a sudden calling to build paper houses, they can follow my instructions (with no particular training from me) and build thousands of houses. More, they can easily predict how much time to spend building this house, the resources involved and to such degree the quality of the product user satisfaction - the 3 ways we evaluate software projects. Which is way more than we can say in our software industry...

[update]
Oops, it seems like I made a serious architectural mistake. Here's an untested patch:


Good to know the other engineers can also make the kind of mistakes we on software development run into :)