Final answer:
The primary drawback of just-in-time manufacturing is the increased risk of supply chain disruptions which can halt production due to its dependency on the timely delivery of parts.
Step-by-step explanation:
The main downfall to just-in-time manufacturing and inventory management is the increased risk of supply chain disruptions. This system depends on the timely delivery of components, and any interruption in the supply chain, such as a strike by workers or a natural disaster, can halt production entirely. The recent COVID-19 pandemic highlighted this vulnerability, as shutdowns and other disruptions led to shortages and slowed production across various industries. Within the JIT model, the absence of large inventories means that there is little to no cushion for delays or unexpected increases in demand, which exacerbates the risks of supply chain disruptions. The reliance on immediate deliveries can also place considerable pressure on suppliers to be located in proximity to the main assembly plants, which in turn can impact labor practices and local economies.