It creates "Supply Shock Inflation." Because there is no back-stock, any minor disruption (snowstorm, strike) causes immediate shortages and price spikes.
Civilization is running on a 72-hour timer. Most grocery stores and hospitals have less than 3 days of essential supplies on hand.
"The Floating Warehouse": Inventory is no longer stored in buildings; it is stored on moving trucks and ships. If the vehicle stops, the inventory effectively disappears.
It forces global homogenization. To work efficiently, JIT requires standardized containers and ports, flattening local economies into nodes of a global grid.
Fragility: The system is optimized for "Blue Sky" scenarios. It has zero tolerance for chaos. A single ship stuck in the Suez Canal can freeze global production for weeks.