Thank you for the opportunity to help you with your question!
i do manage my own personal inventory of various supplies for my small business. I usually do not wait up until i run out of supplies to order replenishing stock, in fact i have lead times which i follow before reordering. this ensures that i always have stock. I avoid ordering after going out of stock due to the various dangers involved with stock outs and late deliveries.
Hope this did assist. Please let me know if you need any clarification. I'm always happy to answer your questions. I will be pleased if you make me your private tutor.