Among other objectives, liquidity guidelines must take into account the risks that inadequate liquidity planning by major financial firms pose for the broader financial system, and they must ensure that these firms do not become excessively reliant on liquidity support from the central bank.
But liquidity risk management at the level of the firm, no matter how carefully done, can never fully protect against systemic events. In a sufficiently severe panic, funding problems will almost certainly arise and are likely to spread in unexpected ways.