Supply chain single vendor – Single buyer inventory model with price-dependent demand

Purpose: The aim of this article is developing an integrated production-inventory-marketing model for a two-stage supply chain. The demand rate is considered as the Iso-elastic decreasing function of the selling price. The main research goal of the article is to obtain the optimal values of the selling price, order quantity and number of shipments for the proposed model under independent and also joint optimization. In addition, the effects of the model’s parameters on the optimal solution are investigated. Design/methodology/approach: Mathematical modeling is used to obtain the joint total profit function of the supply chain. Then, the iterative solution algorithm is presented to solve the model and determine the optimal solution. Findings and Originality/value: It is observed that under joint optimization, the demand rate and the supply chain’s profit are higher than their values under independent optimization, especially for the more price sensitive demand. Therefore, coordination between the buyer and the vendor is advantageous for the supply chain. On the other hand, joint optimization will be less beneficial when there isn’t a significant difference between the buyer’s and the vendor’s holding costs. Originality/value: The contribution of the article is determining the ordering and pricing policy jointly in the supply chain, which contains one vendor and one buyer while the demand rate is the Iso-elastic function of the selling pricePeer Reviewe

Hub Covering Location Problem under Gradual Decay Function

145-148This paper developed a mathematical model framework using the single allocation strategy for hub covering location problem. The model encompassed the transportation time covering under gradual decay function. Within a certain transportation time for the origin and destination nodes among two hubs, the route is fully covered, and beyond another specified transportation time the route is not covered. Between these two given service times, the coverage is linear for the routes. A tabu search has been used to solve some problems such as CAB and AP. The quality of solutions obtained using TS have been compared with the achieved one using CPLEX solver. Plenty of experimental study evaluated the performance of the gradual decay function

A Multi-Product Inventory Model for Selecting the First and Second Layers of Suppliers in a Supply Chain

In recent years, Supplier evaluation and selection, an important element in supply chain management, has been gaining attention in both academic literature and industrial practice. The Mixed integer multi-Objective non-Linear programming model (MIMONLP) presented in this paper aimed to evaluate and select the appropriate set of suppliers considering quantitative and qualitative criteria and in addition to selecting the first layer's suppliers which relate directly to the organization, analyses the characteristics of second-layers suppliers, and design a network to determine the flow rate of products and materials between buyers and best suppliers in both layers. Another important feature of this model is considering holding costs of different products over the planning horizon and quantity discounts for the first layer's suppliers at the same time. Finally, the model is solved by using goal programming approach and numerical examples are presented to test the performance of proposed model

A New Approach for Supplier Selection Process from the Features of Second Layer Suppliers Point of View

In nowadays world competitive market, on account of the development of electronic media and its influence on shortening distances, companies require some core competencies in order to be able to compete with numerous competitors in industry and sustain their situation in such a market. In addition companies achieve this target are those which their processes perform great and exploit from competitive price, quality, guarantee, etc. Since some parameters such as price and quality are so dependent on the performance of company supply chain management, so the results can highly impress the final price and quality of products. One of the main processes of supply chain management is supplier selection process which its accurate implementation can dramatically increase company competitiveness. In presented article two layers of suppliers have been considered as a chain of suppliers. First layer suppliers are evaluated by two groups of criteria which the first one encompasses criteria belongs to first layer suppliers features and the second group contains criteria belong to the characteristics of second layer suppliers. One of the criteria is the performance of second layer suppliers against environmental issues. Then the proposed approach is solved by a method combined of concepts of fuzzy set theory (FST) and linear programming (LP) which has been nourished by real data extracted from an engineering design and supplying parts company. At the end results reveal the high importance of considering second layer suppliers features as a criteria for selecting the best supplier

Incentive mechanism based on cooperative advertising for cost information sharing in a supply chain with competing retailers

Abstract This paper proposes a new motivation for information sharing in a decentralized channel consisting of a single manufacturer and two competing retailers. The manufacturer provides a common product to the retailers at the same wholesale price. Both retailers add their own values to the product and distribute it to consumers. Factors such as retail prices, values added to the product, and local advertising of the retailers simultaneously have effect on market demand. Each retailer has full information about the own added value which is unknown to the manufacturer and other retailer. The manufacturer uses a cooperative advertising program for motivating the retailers to disclose their private information. A numerical study is presented to compare different scenarios of information sharing. Computational results show that there is a condition in which full information sharing is beneficial for all members of the supply chain through cooperative advertising program and, therefore, retailers have enough incentive to disclose their cost information to the manufacturer

Integration of pricing and inventory decision in a supply chain under vendor-managed inventory with defective items and inspection errors: a game-theoretic approach

In this paper, the production-inventory-marketing model for a two-stage manufacturer-retailer supply chain under VMI policy with a price-sensitive demand is studied. An imperfect production at the manufacturer and inspection process involving with Type I and II errors at the retailer are considered. We assume that the manufacturer gives products to the retailer in a number of equal-sized shipments. This model is formulated as a Stackelberg game in which the retailer retains a certain degree of autonomy by reserving the right to choose the retail price and the manufacturer determines replenishment frequency, replenishment quantity and wholesale price. The critical supply chain decision factors including the manufacturer’s wholesale price, the retailer’s price, shipment frequencies and number of shipments are determined maximizing the total profit of each member of the supply chain. A solution procedure is proposed to find the Stackelberg game equilibrium. The performance of the model is assessed by a numerical example. The numerical shows that it is more beneficial for both the manufacturer and the retailer when the demand is less price sensitive

Multi-objective periodic cash transportation problem with path dissimilarity and arrival time variation

This paper introduces a multi-objective periodic routing problem in the context of cash transportation, which attempts to increase security by generating unpredictable alternative paths and spreading arrival times at each demand node. The current study covers the shortcomings of previous models on dissimilar routing and cash transportation problems from several aspects. The studied problem has three objectives, including completion times, risk of robbery, and customers’ satisfaction level considering the effects of traffic congestion as a daily phenomenon. On top of these, we extend the studied routing problem in multigraph setting, which can keep a set of efficient paths with multiple attributes (e.g., risk, time). Such representation enables us to evoke dissimilar route plans not only by reordering the sequence of nodes but also by employing alternative links even in a fix sequence of nodes. To handle the computational challenges arising from these properties, we propose a new evolutionary algorithm based on NSGA-II. The proposed method is embedded with a fuzzy logic technique to guide the applied operators and benefits from caching memory to accelerate and diversify the searching process. The results of implementing the proposed algorithm on test instances confirm the effectiveness of our method in compression to standard NSGA-II. In addition, our performed sensitivity analyses show that the multigraph setting can substantially improve the quality of solutions with respect to all studied objectives

A risk-constrained time-dependent cash-in-transit routing problem in multigraph under uncertainty

The Cash-in-Transit (CIT) deals with the transportation of banknotes, coins, and other valuable items. Due to the high-value density of these products, incorporating security strategies in the carrier operations is crucial. This paper proposes new CIT models involving deterministic and stochastic time-varying traffic congestion. Since risk exposure of a vehicle is proportional to the time-dependent travel time, a new formula is introduced to measure the risk of traveling. Moreover, this study covers one of the important weaknesses of previous CIT routing models by investigating the problem in multigraph networks. Multigraph representation maintains a set of non-dominated parallel arcs, which are differentiated by two attributes including travel time and robbery risk. Considering maximum allowable time duration together with a risk threshold yields to design a more balanced routing scheme. Multi-attribute parallel arcs in a stochastic time-dependent network bring high computational challenges. Herein, we introduce efficient algorithms including a novel flexible restricted Dynamic Programming and a self-adaptive caching Genetic Algorithm. The proposed algorithms are tested on both a real case study in Isfahan metropolis and generated instances. Ultimately, sensitivity analyses are conducted to assess the importance of the use of multigraph networks in the CIT and to provide significant managerial insights for administrators and practitioners