Thanks to Covid-19 almost every supply chain is being re-examined to become more resilient. But there is only so much you can do! There are external factors over which you have no control such as demand changes, up or down, tariffs or dock worker strikes!
At the start of the pandemic the demand (new patients) for PPEs went up dramatically. There were limited amount of supplies and surge in demand for N95 masks, ventilators, hospital beds etc.
Most pharmaceutical companies use S&OP systems in order to perform long term planning of their production. Inventory is a necessary evil.