Why Switzerland stockpiles
When there is a shortage of certain drugs or in case of oil import difficulties, the state intervenes and orders the release of compulsory stocks. However, the Confederation does not run its own warehouses, but obliges companies to maintain sufficient stocks of specific goods.
Read the whole article on swissinfo.ch (in german)

The range is adjusted
The Federal Council determines what belongs in the range of compulsory stocks. The responsibility lies with the Federal Office for National Economic Supply. The range is regularly adjusted.