One of the components used by K Ltd is ordered from a specialist supplier. The daily usage for this component and the time between placing and receiving an order (the lead time) can vary as follows:

Maximum usage

750 per day

Average usage

580 per day

Minimum usage

450 per day

Maximum lead time

15 days

Average lead time

12 days

Minimum lead time

8 day

Calculate the number of units that can be ordered at the re-order level if. As a result of storage problems, the company cannot allow stock to rise above 15 000 units.