Hill, R.M.

policy demand level class lot-for-lot policy inventory order-up-to level demand classes service stock lot-for-lot model 0.5 state critical-level order-up-to system result example priority problem stock level heuristic approach service levels optimisation service level constraints time distribution priority demand classes heuristic critical-level policy sales inventory model solution algorithm probability cost reduction value n demand classes reduction 1 unit arrival demand class dekker order replenishment paper number rationing approach optimization service level inventory model service level optimisation state probabilities table satis fied arrival rate assumption kleijn poisson section distribution unit time state i method cost improvement satis ed research logistics poisson demand computation time expression theorem management science replenishment order increase research make-to-stock production system class j fi xed cost optimization proof