The stochastic inventory models analyzed in this paper explore the problem of lead time associated with setup cost reductions for the continuous review and periodic review inventory models. For these two models with a mixture of backorders and lost sales, we respectively assume that their mean and variance of the lead time demand and protection interval (i.e., lead time plus review period) dema...

Coordinating procurement decisions for a family of products that share a constrained resource, such as an ocean shipping container, is an important managerial problem. However due to the problem’s difficult mathematical properties, efficient and effective solution procedures for the problem have eluded researchers. This paper proposes two heuristics, for the capacitated, coordinated dynamic dem...

a bioreactor equipped with hollow fiber microfiltration membranes was applied for wastewater treatment. removal of chemical oxygen demand (cod) and biochemical oxygen demand (bod5) was investigated. the experimental setup consisted of influent and effluent tanks, and membrane modules using polyvinyl di–fluoride (pvdf) hollow fibers. the operation program included suction and backwash steps whic...

This paper presents a capacitated lot-sizing problem in flow-shop system with energy consideration. The planning horizon is defined by a set of periods. Each period is characterized by demand, duration, electricity cost and maximum peak power. Both non-linear and linear mixed integer programming are proposed to solve the problem with the objective of minimizing the production costs. The costs a...

We present a stylized model for analyzing the e®ect of product variety on supply-chain performance for a supply chain with a single manufacturer and multiple retailers. The manufacturer produces multiple products on a shared resource with limited capacity and the e®ect of changeovers on supply-chain cost is due primarily to setup time rather than setup cost. We show that the expected replenishm...

We examine whether cooperative planning and uncertainty affect the magnitude of rework in concurrent engineering projects with upstream and downstream operations, and explore the impact of such rework on project delays. Using survey data from a sample of 120 business process (BP) redesign and related information technology (IT) development projects in healthcare and telecommunications, our resu...

Inventory model under risk that demand is uncertain is recognized. In this paper, the fuzzy demand per day and fuzzy lead time on a cycle in fuzzy inventory control system are assumed to trapezoidal distribution, trapezoidal fuzzy number by decision maker. A fuzzy inventory model under manager’s preference for order quantity is presented first. This model is given by fuzzy total annual inventor...

We study a variant of the Stochastic Economic Lot Scheduling Problem (SELSP) in which a single production facility must produce several grades to meet random stationary demand for each grade from a common finished-goods (FG) inventory buffer with limited storage capacity. Demand that can not be satisfied directly from inventory is lost. Raw material is always available, and the production facil...

Inventory management studies to minimize the average total cost per unit time and to determine the quantity of the stocked material to be ordered. In this paper the demand follows normal distributive under deterministic, stochastic and mixed environment, respectively and thus the model becomes more realistic. Expected annual cost is measured, with varying defective rate. After that the item wis...