Just in time supply chain model

This is Athul Kumar A and iam quite interested in this topic called 3D printing technology and this interest came when I heard a about it in a online course where it said that this technology helped people in a country (I don't remember the name) to produce mask at almost zero variable cost per unit during the COVID-19 pandemic in march which helped them  provide mask to everyone at very minimal cost compared to the original one. so now i read this article about Just in time supply chain model and how it is made practical by some companies, 

The ongoing drive for profitability and competitive advantage has led companies to increasingly adopt ‘just-in-time’ supply chain models, eliminating the need to maintain vast and costly inventories. As a result, businesses can produce products faster, more cheaply and more efficiently than ever before. But this increased productivity has come at a cost. The process of paring back operations and stripping out all but the most essential redundancy has left supply chains vulnerable to supply interruptions – as was clearly, and dramatically, highlighted by the COVID-19 pandemic.

One likely outcome is that manufacturers will increasingly explore ways to work with suppliers closer to home Supply chains are globalized, even for small to medium sized businesses. This additional complexity to supply chains leaves them more susceptible to disruption in times such as these. The other factor is that, as previously mentioned, ‘just-in-time’ supply chains are great for lean manufacturing, but ‘just-in-time’ does mean that there are fewer buffers to safeguard against disruption. Even a single supplier closure can have a huge trickle-down effect that can shut down assembly lines. 

Ideally, businesses should develop plans to enable them to source essential parts from different regions (both local and overseas). However, this can be tough to do for lower volumes. This is where newer technologies, such as 3D printing and quick turn PCBA manufacturing, enter the frame, as they can be a viable backup solution for many components.

Even before COVID-19, many companies were already using additive manufacturing for spare part production. These include major players in the defence and rail industries where there are high barriers for approval, as well as in aerospace for maintenance and repair. Additive manufacturing eliminates the need for expensive tooling, enabling designers to print low-volume production parts on demand to the exact specification and in the exact numbers required – reducing wait time and safeguarding against external disruptions. Using digital inventories of spare parts, manufacturers can deploy a decentralized production model by 3D printing digital part files directly at the site where it is needed. The ability to print parts on demand in this way can significantly reduce companies’ inventory burden – which, as we have already established, is key to driving down supply chain costs.