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The consignment stock (CS) policy, independently or coupled with vendor managed inventory (VMI), has been practised by businesses and shown to be profitable. It helps to reduce or eliminate out-of-stock instances caused by fluctuations in demand. CS brings several benefits to collaborating parties. Unlike the two-level supply chain models in the literature, this paper considers a three-level supply chain that consists of a supplier, a vendor and a buyer with CS policy agreements. The paper also examines four coordination scenarios (a combination of traditional and CS) in conjunction with a payment scheme between adjacent parties. Nine coordination cases (models) are provided. A sensitivity analysis is performed to study the effects of some parameters on the performance of the developed models. Most of the results showed that a combination of traditional and CS policies returned a higher total system profit. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the role of trust in supply forecast signalling in a supply chain with a supplier and a manufacturer in a one-shot game. It is assumed that the supplier faces a random yield uncertainty that is multiplied by the manufacturer’s order quantity. The supplier has a private forecast of yield risk. Based on the information, the supplier decides whether to share its forecast truthfully, or not to share. On the other hand, the manufacturer is faced with two ordering strategies. If it trusts the supplier’s report, then it updates its belief on the yield risk providing a forecast signal by the supplier. Otherwise, it orders based on its prior belief. We analytically obtain the optimal order quantity where the random yield uncertainty follows uniform distribution. The intuitive result indicates that the supplier has a tendency to deviate from reporting true forecast information. The numerical results support the intuitive conclusion. [ABSTRACT FROM AUTHOR]

This paper presents a vendor-managed inventory (VMI) with consignment stock (CS) policy applied to the integrated vendor–buyer system, where the demand at the buyer side is stock dependent. Under the VMI with CS, the vendor manufactures a product and delivers it in batches of equal sizes to the buyer: although the goods are in the warehouse of the buyer, they remain to be the property of the vendor until the buyer registers a withdrawal. The products delivered are presented to the end customers in a display area and the demand is assumed to be positively dependent on the number of items displayed. Moreover, the model proposed considers that the product display area is replenished once its inventory level hits a given minimum. The paper investigates and compares different policies that may be adopted to exploit the advantages offered by the consignment stock agreement when stock dependent demand at the buyer side is considered. [ABSTRACT FROM AUTHOR]

Order picking (OP) activities, essential to logistics operations, are laborious and time-intensive. Humans are central actors in the OP process and determine both OP effectiveness and efficiency. Many researchers have developed models for planning OP activities and increasing the efficiencies of such systems by suggesting different warehouse layouts, OP routes or storage assignments. These studies have, however, ignored workers’ characteristics, or human factors, suggesting that they cannot be substantiated, which led to only partially realistic results. This paper proposes a conceptual framework for integrating human factors into planning models of OP activities and hypothesises that doing so improves the performance of an OP system and workers’ welfare. The framework is based on a systematic literature review that synthesises findings documented in the OP and human factors literature. The results of the paper may assist researchers and practitioners in designing OP systems by developing planning models that help in enhancing performance and reducing long-term costs caused by work-related inefficiencies. [ABSTRACT FROM PUBLISHER]

This paper extends the model of a production, remanufacturing and waste disposal system by adding a buyer (retailer) to the vendor’s system to form a two-level forward/reverse supply chain. The vendor and the buyer are assumed to operate according to a consignment stock policy. A mathematical model is developed for the cases when the production and remanufacturing batches are of different and equal sizes. The model also accounts for transportation, inspection and sorting costs. Numerical examples are provided and results are discussed. The results show that the collection rate of used items and the repairable rate have a significant impact on the total cost of the system and the batch sizes. It was suggested that it may not be possible to operate a system like the one described in the paper at its maximum environmental edge without receiving some incentives or tax brackets. Another possibility is for the system to undergo a continuous improvement process to reduce its operational costs, which may require additional investment. [ABSTRACT FROM PUBLISHER]

This paper presents a joint economic lot size (JELS) model for coordinated inventory replenishment decisions under the vendor-managed inventory (VMI) with consignment stock (CS) agreement and an emission-trading scheme. The paper assumes a single product that flows along a two-level supply chain system, with a single vendor and a single buyer. The total cost of the system is the performance measure, which is the sum of the vendor’s and the buyer’s total costs. The total cost includes the set-up and order costs, inventory holding costs, greenhouse gases (GHG) emissions tax and penalty costs. A mathematical model is proposed to determine: (1) the vendor’s production lot size quantity; (2) the number of shipments sent by the vendor to the buyer in a cycle; and (3) the production rate that minimises the total cost of the supply chain. Some numerical examples are carried out, as well as comparisons with the traditional JELS model for a classic two-level supply chain. Results show that the performance of the system is better when it is operated under a VMI with CS agreement, which is capable of reducing the traditional inventory holding costs and, for some values of given parameters, the GHG emissions tax and penalty costs. [ABSTRACT FROM PUBLISHER]

This paper presents a joint economic lot size (JELS) model for coordinated inventory replenishment decisions considering price and environmentally sensitive demand. It assumes a single product that flows along a two-level supply chain (vendor-buyer). The buyer's demand is linear and sensitive to the product's price and its environmental performance. A capital investment is considered necessary to improve the production process resulting in an indirect improvement of the product's environmental quality. A mathematical model is developed to represent this situation and solved to maximize the total profit of the supply chain for: (1) the vendor's production lot size quantity and the number of shipments to the buyer, and (2) the selling price and the amount invested to improve the production process. Numerical examples are provided with their results discussed. [ABSTRACT FROM AUTHOR]

Learning associated with mechanical computer-aided design (CAD) poses challenges for both trainers and trainees. This article presents findings that relate to the acquisition of skills in utilizing a modern mechanical CAD tool, Pro/ENGINEER version 2000i2, to design models of low complexity. Empirical learning curves were generated and broken into declarative and procedural components, which were analyzed in an attempt to measure how and how fast trainees developed cognitive and motor skills. Results showed that there is an inverse relationship between the amount of improvement in performance time and the number of build features used in building a solid model. If production time is an overriding criterion, then efforts should be focused on teaching CAD trainees how to build mechanical solid models using small number of complex, more time-efficient features. [ABSTRACT FROM AUTHOR]

The physical characteristics of stocked items dictate the nature of inventory policies implemented to manage and control. The traditional economic order quantity model (EOQ ) assumes that items stocked preserve their characteristics during their stay in inventory. The question is how reliable are the EOQ modelswhen items stocked deteriorate over time. This paper introduces a modified EOQ model in which it assumes that a percentage of the on-hand inventory is wasted due to deterioration. A mathematical model is developed and numerical examples provided to illustrate the solution procedure. [ABSTRACT FROM AUTHOR]

This paper studies the effects of learning and forgetting on the production lot size problem with infinite and finite planning horizons. It is assumed that the determination of the economic manufactured quantity (EMQ) in the succeeding production run is dependent on: (1) the maximum inventory accumulated prior to interruption; (2) the length of the interruption period which incurs total forgetting; and (3) the level of experience in equivalent units remembered at the start-up of the next production run. The optimum operating inventory doctrines is obtained by trading off procurement cost per unit time and the inventory carrying cost per unit time, so that their sum will be a minimum. A numerical example is presented to demonstrate the application of learning and forgetting to the determination of the EMQ. [ABSTRACT FROM AUTHOR]