The Bohai Economic Rim plays an important role in supporting China’s economic growth. For this research, we selected nine main ports in the region to study whether intra-port competition or corporatization would improve efficiency. Using a panel fixed effect model and stochastic frontier model, we found that the technical efficiency of selected ports is significantly influenced by the time of t...

Economic Order Quantity (EOQ) model has been extended. We formulate EOQ model as a calculus of variations. This new extended problem is a simple optimal control problem with an unknown initial state. By solving this problem we generalize EOQ formula [1].

a r t i c l e i n f o JEL classification: C02 M11 C44 C61 Keywords: Multi-item production system Rotation cycle time Multi-delivery Economic production quantity model Scrap Vendor–buyer integrated system This paper addresses the joint determination of a rotation cycle time and number of shipments for a multi-item economic production quantity (EPQ) model with random defective rate. The classic E...

EPQ model; Replenishment lot size; Multiple deliveries; Random defective items; Production; Rework; Scrap items. Abstract This paper derives the optimal replenishment lot size and shipment policy for an Economic Production Quantity (EPQ) model with multiple deliveries and rework of random defective items. The classic EPQmodel assumes a continuous inventory issuing policy for satisfying demand a...

The demand pattern for most perishable products varies during their life cycle in the market. These variations must be properly reflected in inventory management in order to prevent unnecessary stock-out or excess inventory with associated increase in cost. In this paper, a multi-period economic order quantity (EOQ) model for managing the inventory of perishable items having varying demand patt...

In this paper, an inventory model for two-stage supply chain is investigated. A supply chain with single vendor and single buyer is considered. We assume that shortage as a backorder is allowed for the buyer and the vendor makes the production set up every time the buyer places an order and supplies on a lot for lot basis. With these assumptions, the joint economic lot size model is introduced ...

This paper considers the basic economic order quantity (EOQ) model when all parameters, such as the demand rate, the ordering cost, and the inventory holding cost, are uncertain, and furthermore, their probability information is also unknown. To address the uncertainty, we adopt a robustness-based approach. In this approach, each unknown parameter is described as a continuous value restricted t...

Deciding shipment size is important in freight transport: it depends on the logistical imperatives of shippers and the technical possibilities of carriers. Shipment size choice is also closely related to transportation mode; it is therefore important from a public policy perspective. The theory of optimal shipment size and mode choice is robust. There are many inventory-theoretical models of op...

We review historical patterns of "economic geography" for the United States from the colonial period to the present day. The analysis is framed in terms of two geographic scales: regions and cities. The compelling reason for studying geographic areas of different scales is that models that explain the location of economic activities at one scale many not apply to other scales. We consider the p...

The main purpose of this paper wants to investigate the optimal retailer’s lot-sizing policy with two warehouses under partially permissible delay in payments within the economic order quantity (EOQ) framework. In this paper, we want to extend that fully permissible delay in payments to the supplier would offer the retailer partially permissible delay in payments. That is, the retailer must mak...