While many of the properties of surface modeling were already familiar to me, the reading from Digital Design Manufacturing by Daniel Schodek did an excellent job at covering the basics of various digital modeling techniques. The distinctions between parametric design, dimensionally-driven design, design constraints, and parent-child relationships are seemingly subtle at times, but important definitions that I had not previously encountered. The discussed workflow of making late-game changes to parent features that affect several base features raises the question: at what point is the time saved in making these changes greater than the time expended to establish the parent-child relationships in the first place?
Conceptually, I understand the power of establishing such relationships and making changes within the rule set initially conceived; however, when the changes include modifications to that rule set, there are often unforeseen implications to children which compound in complexity with each level of dependency. In my experience, it is not uncommon to make such rule-based changes to the parent, and find that the children essentially break as a result, and all the initial work of establishing the rule set must be redone. Schodek addresses this briefly in the introduction to Chapter 11 with the caveat that programs like CATIA are intended for design development, not conceptual design, wherein the designer will have fairly defined preconceptions of the intended output, and therefore will be able to forecast necessary rule sets for parent features. This ability might also just come with experience using the software and understanding how to develop robust parent-child relationships.
Schodek also touches on finite-element analysis as a method to test digital models using simulated real-world stresses. I enjoyed the disclaimer that such tools are powerful, but not to be trifled with by those without the proper knowledge of structural behavior. Given that the user is knowledgeable, it seems that this facet of digital modeling is paramount to its ability to translate to a successful fabricated product, and allows the designer to remove much of the process of analysis from the physical realm thereby greatly streamlining the feedback loop.