I've spent some time thinking about this from an automotive manufacturing perspective (I work for an automotive manufacturer, previously on the shop floor). En

I've spent some time thinking about this from an automotive manufacturing perspective (I work for an automotive manufacturer, previously on the shop floor). Engineering is all about trade-offs - both physically/materially/technically, and in time and money. As an engineer/designer you have a set of requirements to meet: Product Safety, Customer Needs, Marketing Needs, and Technical Requirements. Then you can spend some time on Serviceability - but any time and money you spend on Serviceability is time you are not spending on improving the product and hopefully reducing the need to repair and replace parts in the first place. Then you start manufacturing the thing, and problems come out of the woodwork. If you put a thousand parts together that's at least two thousand things to go wrong (and often many more). So you spend time designing for manufacturability/assembly - add an alignment slot to this connector, color coordinate these parts so it's obvious what goes together, make this bolt/fastener easier to insert. This is called Poke-Yoke, or idiot proofing. You spend a lot of time on this because there are a lot of idiots. If you are good at manufacturing you learn how to make the thing quickly, with high quality, and with a small number of workers. This is called Lean Manufacturing. The upshot of all of this, is that the connectors, parts, assemblies, fasteners, adhesives and all of that are designed so that the widget goes together right the first time, in such a way that an idiot can put it together, and it should work for a long time.