Will it run out before the next delivery? For the — busiest stocked items as of —, stock on hand plus what arrives within the lead time is set against demand — once with aito..'s forecast, once with the trailing average a plain ERP reorder rule uses. The following month is held out, so both answers are checked against its actual sales rate: would stock have lasted the lead time at the rate that really sold? One month's rate, projected, not a count of empty-shelf days.