Design for manufacturability (DFM) is an important area of electronics and mechanical engineering. As this modern way of approaching device design is focused on reducing the difficulty in building mass manufactured goods. Accordingly, the device unit cost usually becomes lower in higher volumes, so more people can afford to use a given widget. Indeed, almost every mass-manufactured consumer product people purchase these days is based on this practice.

However, DFM almost always includes design compromises to reduce the costs of building a widget, and budgets are often bid down over time as market competition is applied to further reduce unit cost.  This leads to a reduction of the expected bathtub-curve device reliability period, and often results in a rather limited operational life for modern hardware. Thus, replaceable consumer devices that wear-out after awhile rather than requiring maintenance are very common, and in many cases preferred by nontechnical people.

Home based 3D printing & milling may one day change how some people make devices, but in general the consumables like wire/filament/end-mills are still mass manufactured using the traditional methodologies. 

Conversely, true industrial equipment is usually built around a regular maintenance cycle, and often prioritizes service life over other design goals. After looking at long-service life machinery (running over 10+ years), we came to some conclusions others may find useful: 

• Designs that use a wear-in rather than wear-out mechanism philosophy will tend to age gracefully where parts fail gradually rather than catastrophically (often giving the operator a clear advanced hint the device is losing functionality)
• Replaceable bearings with automatic oil drip feeds will maintain useful precision longer
• Machinable wear surfaces for rebuilding worn out parts
• Exposed drive mounting plates and drive pulleys allow control system rebuilds decades later
• Easy to inspect embossed labels in wiring cabinets with laminated schematics allow people to understand how these mechanisms are supposed to work years later
• No blind bolt holes in the casting, and sheet metal covers
• Simple part shapes that do not require a complex casting
• Large holes in the machine body safe for chain rigging to a hoist and crane (i.e. movers won't shear off something)
• all non-recessed parts clearly embossed, and are removable with pins or bolts