Under what circumstances would the amount of safety stock hold to be zero?

The safety stock is zero when the company has a policy not to keep any inventory on hold. The just-in-time (JIT) system states that inventory should be ordered when required and not held up in the warehouse. A company that follows the JIT system will have zero safety stock. JIT company has arrangements with suppliers, and inventory will be provided as and when required. It reduces the inventory holding cost.