Thinking [in terms of loops and arcs] allows us to let go of a specific journey or sequence, and imagine dozens of scenarios and possible sequences in which these skills can be learned. This doesn’t mean there aren’t more fundamental skills that other skills build upon, but we can let go the tyranny of how, precisely, a person will move through a system. We’re free to zoom in and obsess on these loops, which does two things for us:
Approach the design of a system as the design of these as small but significant moments of learning.
Consider the many ways these loops might be sequenced, with the exact order being less important.
Engineers seem to have a clear, if usually implicit, model of the process of design. It is usually an orderly model of an orderly process as the engineer conceives it.
The notion that the design process should be modeled as a systematic step-by-step process seems to have first developed in the German mechanical engineering community.
Herbert Simon independently argues for design as a search process in The Sciences of the Artificial. He was motivated to lay out a strictly rational model of design precisely because such a model was a necessary precursor to automating design. His model remains influential even if today we recognize the "wicked problem" of original design as one of the least promising candidates for AI.
In software engineering, Winston Royce independently introduced a seven-step Waterfall Model to bring order to the process. In fact, Royce introduced his waterfall as a straw man that he then argued against, but many people have cited and followed the straw man rather than his more sophisticated models. Even if ironically, Royce's seven-step model must be considered one of the foundational statements of the Rational Model of Design.