[Header image credit: Wikipedia]

I have been interested in 3D printing (the technical name should be “Additive Manufacturing”) for the last 10 years, but why can it be a real alternative to the traditional manufacturing, at least to some industries?

  • Just from a pure physics perspective, AM can make products that other methods cannot. For example, products with complicated interior structure (deep channels, contorted shapes, blind holes, nesting parts). For example, we now have 3D-printed airway stents approved by FDA already.
  • More importantly, there are products that do not have, or do not need, scale of economy in manufacturing. Two kinds of products came to my mind:
    • One-of-a-kind products (i.e. customized): Dentures, or custom-fit shoes
    • Very low demand rate but high holding cost: some special parts in a jet engine
    • Outdated products whose parts are not made any more: antique cars
  • Where transportation of parts is either too expensive or too time-consuming. For example, it may be more cost-effective to 3D-print a house in some locale than to assemble one.

Connor (2014) describes an interesting paradigm in thinking about manufacturing, which can be summarized in the following graph:

Connor et al (2014): Making sense of 3-D printing: Creating a map of additive manufacturing products and services, Additive Manufacturing

The authors essentially evaluate manufacturing on three dimensions: volume, customization, and complexity. While this is a helpful way to evaluate AM, I do not think volume should be a major concern. This is because volume is only necessary in traditional manufacturing as a means to drive unit cost down. So perhaps cost per unit should be the criteria instead. I also think quality should be a criteria.

AM also excels in another dimension: delivery and lead time. To be sure, AM needs its own supply chain: AM machines, power supply, and material are all important in enabling AM production. But AM supply chain is much simpler, and overall production lead time could be much shorter, compared to the traditional way, in the sense that AM products can be delivered on-site. Of course, we need a more comprehensive study to compare the total lead time, so this is just a conjecture at this point. But from real-life examples of 3D-printed houses and bridges, lead time does seem to be an advantage.

AM may be better on the sustainability front. First, making things additively may be more energy-efficient, I suspect, although that needs to be researched and verified. Second, I also suspect AM may be more amenable to recycling. In particular, people may pay more attention to how recyclable the inputs are.

In sum, AM is proving itself to be an ever-promising manufacturing paradigm.