Lee, C.Y.

period demand replenishment replenishment periods window problem demand time windows algorithm model lot-sizing lot-sizing model inventory period t demand time window management complexity backordering property lot-sizing problem backlogging value scheduling research production time windows solution order delivery time window replenishment period science planning polynomial time algorithms backordering cost quantity satis fied customer wagelman /procurement cost 1 ≤ operation paper assumption m 0 t section formulation operations research replenishment order /procurement management science equation li ≤ t planning horizon programming demand i amount backordering costs notation lot-size university vehicle ç etinkaya replenishment quantity lot-size model grace period polynomial shortage definition · · · ks ks +1 production planning department engineering report etinkaya supply transportation number replenishing management sci