Yesterday, I experienced how things that we take for granted can all suddenly go off the rails when the most basic practice is not followed. How complex systems, even when that complexity is carefully hidden from end users, can fail at the most inopportune time, and for the simplest reason. How this can affect the confidence you have placed in that system, thus making you think that you might need a new and better one, with more features, etc. So when dealing with complex systems, we should always remember that the more critical the system 1-the more important all the practices around it become. 2-the more important the non-functional requirements become and 3-the more important the relationships with your users become.