Lead Time Calculator

This calculator adds the stages of an order into one total lead time, and separately works out the reorder point and safety stock that lead time calls for. The first mode takes order preparation, supplier production, transit, receiving and any safety buffer in days, and returns the total with each stage as a share of it and the date you would have to order by. The second takes average daily demand, its standard deviation, the average lead time and its standard deviation, and a cycle service level, and returns the safety stock and the level of stock at which to reorder. The service level factor is the normal quantile, computed rather than read off a short table, so any figure between 50 and 99.99 percent works.