The cost of some shortages is measured in lives. With such shortages, preventing the shortage is better than mitigating the shortage. Mitigating the shortage is

The cost of some shortages is measured in lives. With such shortages, preventing the shortage is better than mitigating the shortage. Mitigating the shortage is in turn better than not mitigating the shortage. A buffer gives us time. That time can be used to save lives. A buffer absorbs a short term disruption in a supplier which prevents the shortage. A buffer gives time to look for another supplier in a long term disruption. A buffer delays a shortage when no other supplier is feasible.