scholarly journals Analysis of the effects of Lead-Time variation and Lateral Transshipment insertion in a Supply Chain Network

Author(s):  
Mohamed Salim Amri Sakhri ◽  
Mounira Tlili ◽  
Ouajdi Korbaa

Abstract In a supply chain, inventory is the single largest source of costs for a company. This is due to the various physical and informational activities that accompany inventory management, primarily the holding and transportation of inventory. Companies are looking to streamline these activities and minimize the associated costs. One of the most coveted models to jointly solve these two problems is the Inventory Routing Problem (IRP), which will be the focus of this study. This paper addresses the case of a deterministic replenishment demand in a distribution network consisting of a supplier and a number of customers to be served by a single vehicle over a finite planning horizon. We will first study the impact of increasing supplier lead times on network costs. Then, we will study the effects of the Lateral Transshipment (LT) technique on the overall network cost. A mathematical model is developed and solved by an exact method. The results obtained will show that LT is an effective tool capable of improving the total network cost and balancing the customers’ inventory level.

Author(s):  
Zhenzhen Zhang ◽  
Zhixing Luo ◽  
Roberto Baldacci ◽  
Andrew Lim

The production routing problem (PRP) arises in the applications of integrated supply chain which jointly optimize the production, inventory, distribution, and routing decisions. The literature on this problem is quite rare due to its complexity. In this paper, we consider the multivehicle PRP (MVPRP) with order-up-to-level inventory replenishment policy, where every time a customer is visited, the quantity delivered is such that the maximum inventory level is reached. We propose an exact Benders’ decomposition approach to solve the MVPRP, which decomposes the problem as a master problem and a slave problem. The master problem decides whether to produce the product, the quantity to be produced, and the customers to be replenished for every period of the planning horizon. The resulting slave problem decomposes into a capacitated vehicle routing problem for each period of the planning horizon where each problem is solved using an exact algorithm based on the set partitioning model, and the identified feasibility and optimality cuts are added to the master problem to guide the solution process. Valid inequalities and initial optimality cuts are used to strengthen the linear programming relaxation of the master formulation. The exact method is tested on MVPRP instances and on instances of the multivehicle vendor-managed inventory routing problem, a special case of the MVPRP, and the good performance of the proposed approach is demonstrated.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Parviz Fattahi ◽  
Mehdi Tanhatalab

Purpose This study aims to design a supply chain network in an uncertain environment while exists two options for distribution of the perishable product and production lot-sizing is concerned. Design/methodology/approach Owing to the complexity of the mathematical model, a solution approach based on a Lagrangian relaxation (LR) heuristic is developed which provides good-quality upper and lower bounds. Findings The model output is discussed through various examples. The introduction of some enhancements and using some heuristics results in better outputs in the solution procedure. Practical implications This paper covers the modeling of some real-world problems in which demand is uncertain and managers face making some concurrent decisions related to supply chain management, transportation and logistics and inventory control issues. Furthermore, considering the perishability of product in modeling makes the problem more practically significant as these days there are many supply chains handling dairy and other fresh products. Originality/value Considering uncertainty, production, transshipment and perishable product in the inventory-routing problem makes a new variant that has not yet been studied. The proposed novel solution is based on the LR approach that is enhanced by some heuristics and some valid inequalities that make it different from the current version of the LR used by other studies.


Kybernetes ◽  
2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Misagh Rahbari ◽  
Seyed Hossein Razavi Hajiagha ◽  
Mahdi Raeei Dehaghi ◽  
Mahmoud Moallem ◽  
Farshid Riahi Dorcheh

Purpose In this paper, multi-period location–inventory–routing problem (LIRP) considering different vehicles with various capacities has been investigated for the supply chain of red meat. The purpose of this paper is to reduce variable and fixed costs of transportation and production, holding costs of red meat, costs of meeting livestock needs and refrigerator rents. Design/methodology/approach The considered supply chain network includes five echelons. Demand considered for each customer is approximated as deterministic using historical data. The modeling is performed on a real case. The presented model is a linear mixed-integer programming model. The considered model is solved using general algebraic modeling system (GAMS) software for data set of the real case. Findings A real-world case is solved using the proposed method. The obtained results have shown a reduction of 4.20 per cent in final price of red meat. Also, it was observed that if the time periods changed from month to week, the final cost of meat per kilogram would increase by 43.26 per cent. Originality/value This paper presents a five-echelon LIRP for the meat supply chain in which vehicles are considered heterogeneous. To evaluate the capability of the presented model, a real case is solved in Iran and its results are compared with the real conditions of a firm, and the rate of improvement is presented. Finally, the impact of the changed time period on the results of the solution is examined.


2011 ◽  
Vol 204-210 ◽  
pp. 915-918
Author(s):  
Xin Yi Bu ◽  
Fang Zhou Teng

It is usually observed in the supermarkets that display of deteriorating items. These items are with short shelf life and difficult to be transported and stored. A supply chain conceptual model which consists of one supplier and two retailers is structured. Based on analysis of deteriorating inventory model in exist, the transshipment between the two retailers is added into the supply chain conceptual model and a deteriorating model is developed in this paper which can reflect more accurately the relation among inventory level, demand rate, deteriorating rate and lateral transshipment rate. The ordering policy taking into account the shelf life constraint is investigated with two last ordering opportunities on condition that the planning horizon can be modified based on the lateral transshipment. At last, the conclusion implies that the ordering policy for deteriorating items with short shelf life based on the lateral transshipment can improve the profit for the retailer.


2020 ◽  
Vol 12 (11) ◽  
pp. 4735
Author(s):  
Mingyuan Wei ◽  
Hao Guan ◽  
Yunhan Liu ◽  
Benhe Gao ◽  
Canrong Zhang

The research on production, delivery and inventory strategies for perishable products in a two-echelon distribution network integrates the production routing problem (PRP) and two-echelon vehicle routing problem (2E-VRP), which mainly considers the inventory and delivery sustainability of perishable products. The problem investigated in this study is an extension of the basic problems, and it simultaneously optimizes production, replenishment, inventory, and routing decisions for perishable products that will deteriorate over the planning horizon. Additionally, the lead time has been considered in the replenishment echelon, and the unit inventory cost varying with the inventory time is considered in the inventory management. Based on a newly designed model, different inventory strategies are discussed in this study: old first (OF) and fresh first (FF) strategies both for the first echelon and second echelon, for which four propositions to model them are proposed. Then, four valid inequalities, including logical inequalities, a ( ℓ , S , W W ) inequality, and a replenishment-related inequality, are proposed to construct a branch-and-cut algorithm. The computational experiments are conducted to test the efficiency of valid inequalities, branch-and-cut, and policies. Experimental results show that the valid inequalities can effectively increase the relaxed lower bound by 4.80% on average and the branch-and-cut algorithm can significantly reduce the computational time by 58.18% on average when compared to CPLEX in small and medium-sized cases. For the selection of strategy combinations, OF–FF is suggested to be used in priority.


Mathematics ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 382 ◽  
Author(s):  
Muhammad Imran ◽  
Muhammad Salman Habib ◽  
Amjad Hussain ◽  
Naveed Ahmed ◽  
Abdulrahman M. Al-Ahmari

This paper presents a multi-objective, multi-period inventory routing problem in the supply chain of perishable products under uncertain costs. In addition to traditional objectives of cost and greenhouse gas (GHG) emission minimization, a novel objective of priority index maximization has been introduced in the model. The priority index quantifies the qualitative social aspects, such as coordination, trust, behavior, and long-term relationships among the stakeholders. In a multi-echelon supply chain, the performance of distributor/retailer is affected by the performance of supplier/distributor. The priority index measures the relative performance index of each player within the supply chain. The maximization of priority index ensures the achievement of social sustainability in the supply chain. Moreover, to model cost uncertainty, a time series integrated regression fuzzy method is developed. This research comprises of three phases. In the first phase, a mixed-integer multi-objective mathematical model while considering the cost uncertainty has been formulated. In order to determine the parameters for priority index objective function, a two-phase fuzzy inference process is used and the rest of the objectives (cost and GHG) have been modeled mathematically. The second phase involves the development of solution methodology. In this phase, to solve the mathematical model, a modified interactive multi-objective fuzzy programming has been employed that incorporates experts’ preferences for objective satisfaction based on their experiences. Finally, in the third phase, a case study of the supply chain of surgical instruments is presented as an example. The results of the case provide optimal flow of products from suppliers to hospitals and the optimal sequence of the visits of different vehicle types that minimize total cost, GHG emissions, and maximizes the priority index.


2011 ◽  
Vol 58-60 ◽  
pp. 2141-2146
Author(s):  
Xiao Di ◽  
Bao Xing

Based on demand uncertainty, the paper studies inventory management decision of two competing supply chains from the perspective of customer service. The paper mainly discusses two different inventory strategies, which are widely used, that is, consignment stock and VMI, and analyzes the optimal policies under three competitive scenarios, which consist of using consignment stock in both supply chains (CC mode), using VMI in both supply chains (DD mode), and using consignment stock in one supply chain but VMI another (VC mode). The paper compares equilibrium inventory level and profit of supply chain in different competitive modes, and concludes that both supply chains use VMI is equilibrium, which means that when manufacturers have right to choose inventory management policy, they prefer VMI. But it isn’t paradoxical with the phenomenon that consignment stock is common in reality, because manufacturers are forced to use consignment by retailer’s channel power.


2013 ◽  
Vol 409-410 ◽  
pp. 1089-1092
Author(s):  
Wei Yang Zhao ◽  
Bin Zhang

The paper establishes an inventory routing integrated model to economize the supply chain cost based on a supply chain composed of a single supplier, a third party logistics enterprise and multiple retailers. First of all, the paper acquires the optimal path arrangement for the third party logistics vehicles and the initial fixed partition through ant colony algorithm. Secondly, the paper calculates the total cost of the supply chain through the integral multiple sampling period and the fixed partition policies. Finally, the paper adjusts the third party logistics replenishment period for different partitions until the cost of supply chain comes to the minimum.


2015 ◽  
Vol 21 (4) ◽  
pp. 928-963 ◽  
Author(s):  
Anna Corinna Cagliano ◽  
Alberto De Marco ◽  
Carlo Rafele ◽  
Andrea Bragagnini ◽  
Luca Gobbato

Purpose – The purpose of this paper is to propose a systemic methodology to assess the potential of and facilitate policies for the diffusion of a smartphone based service enabling supply chain (SC) operations in the e-grocery sector. Design/methodology/approach – A System Dynamics (SD) model combining the Bass paradigm for innovation diffusion and an inventory management framework is developed. Semi-structured interviews are conducted to understand the industry business processes; a simple SD model is designed to capture the most important variables together with the relationships among them; a detailed SD model is calibrated and simulation outcomes are analysed. Findings – The efficiency and reliability of the service drive its diffusion among producers and consumers, who in turn persuade retailers to adopt. The assessment methodology can be part of feasibility studies and marketing investigations in order to understand the impact of e-commerce tools on SC processes. Research limitations/implications – This contribution stresses the need to analyse how mobile information technologies may benefit all the business processes of the e-grocery SC, and not just one single process or stakeholder. Practical implications – The approach offers a roadmap to identify the factors influencing the diffusion of mobile e-grocery services as well as the associated impacts on SC processes. Originality/value – The work contributes to overcoming the lack of approaches studying the diffusion of e-grocery by taking into account all the relevant aspects and stakeholders involved and not only the consumer perspective.


Sign in / Sign up

Export Citation Format

Share Document