scholarly journals Optimal inventory policy for the two-level supply chain with defective items

2021 ◽  
Author(s):  
S. M. Hafiz Al Mamun
Keyword(s):  
Supply Chain ◽  
Inventory Management ◽  
Project Work ◽  
High Tech ◽  
Optimum Number ◽  
Screening Process ◽  
Defective Items ◽  
Expected Cost ◽  
Holding Costs ◽  
Shipping Costs

This project focuses on two-level closed-loop supply chains with defective items. The objective of this project is to develop and design a model that minimizes the total expected cost per unit time, which includes set-up costs, holding costs, transportation/shipping costs, and screening costs of the integrated two-level close-loop supply chain. The model also finds the optimum order size and optimum number of shipments. The buyer screens the products received from the vendor to find the defective items. The holding costs of the defective items at the buyer's end is paid by the vendor. After the screening process, the defective items are shipped back to the vendor and the vendor has to carry the shipping costs of the defective items. Two scenarios may arise: where both the vendor and buyer are domestic or international, where vendor and buyer are located in two different countries. In the case of an international supply chain, exchange rate between two countries has also been considered. In current world since the business growing fast, the inventory management of any business enterprise improving their performance financially by minimizing the holding cost. The analysis shows how the percentage of defective item affects the total expected cost. The project work has an important involvement for improvement in the vendor-buyer correlated high-tech supply chain industries.

scholarly journals Optimal inventory policy for the two-level supply chain with defective items

2021 ◽  
Author(s):  
S. M. Hafiz Al Mamun
Keyword(s):  
Supply Chain ◽  
Inventory Management ◽  
Project Work ◽  
High Tech ◽  
Optimum Number ◽  
Screening Process ◽  
Defective Items ◽  
Expected Cost ◽  
Holding Costs ◽  
Shipping Costs

This project focuses on two-level closed-loop supply chains with defective items. The objective of this project is to develop and design a model that minimizes the total expected cost per unit time, which includes set-up costs, holding costs, transportation/shipping costs, and screening costs of the integrated two-level close-loop supply chain. The model also finds the optimum order size and optimum number of shipments. The buyer screens the products received from the vendor to find the defective items. The holding costs of the defective items at the buyer's end is paid by the vendor. After the screening process, the defective items are shipped back to the vendor and the vendor has to carry the shipping costs of the defective items. Two scenarios may arise: where both the vendor and buyer are domestic or international, where vendor and buyer are located in two different countries. In the case of an international supply chain, exchange rate between two countries has also been considered. In current world since the business growing fast, the inventory management of any business enterprise improving their performance financially by minimizing the holding cost. The analysis shows how the percentage of defective item affects the total expected cost. The project work has an important involvement for improvement in the vendor-buyer correlated high-tech supply chain industries.

scholarly journals Inventory control in a two-level supply chain with learning, quality and inspection errors

2021 ◽  
Author(s):  
Mehmood Khan
Keyword(s):  
Supply Chain ◽  
Product Quality ◽  
Inventory Management ◽  
Human Error ◽  
Threshold Value ◽  
Process Quality ◽  
Lot Size ◽  
Defective Items ◽  
Inspection Errors ◽  
Screening Cost

A common measure of quality for a buyer or a vendor is the defect rate. Defects may represent an attribute, a dimension or a quantity. They may be classified as product quality defects or process quality defects. Product quality defects may be caused by human error which can de due to fatigue, lack of proper training, or other reasons. For example, an inspector may misclassify a defective fuel tank of a car as good. On the other hand, process quality defects maybe caused by a machine going out-of-control. While many researchers assume that the screening processes which separate the defective items are error-free, it would be realistic to consider misclassification errors in this process. Beside inspection errors, learning is another human factor that brings in enhancement in the overall performance of a supply chain. Learning is inherent when there are workers involved in a repetitive type of production process. Learning and forgetting are even more important in manufacturing environments that emphasize on flexibility where workers are cross-trained to do different tasks and where products have a short life cycle. Inventory management with learning in quality, inspection and processing time will be the focus of this thesis. A number of models will be developed for a buyer and/or a two level supply chain to incorporate these human factors. The key findings of this work may be summarized as 1. Inspection errors significantly affect the annual profit. 2. An increase in the unit screening cost reduces the annual profit to a great extent at slower rates of learning. 3. For the two-level supply chain we investigated, learning in production drops the annual cost significantly while the learning in supplier's quality results in a situation where there are no defectives from the suppliers. 4. Type II error may seem to be beneficial for a two level supply chain as the order/lot size goes down and thus affects the costs of ordering, production and screening. 5. Consignment stocking policy performs better than conventional stocking when holding costs go higher than a threshold value.

Supply chain models with imperfect quality items when end demand is sensitive to price and marketing expenditure

2018 ◽  
Vol 52 (3) ◽  
pp. 725-742 ◽  
Author(s):  
Rita Yadav ◽  
Sarla Pareek ◽  
Mandeep Mittal
Keyword(s):  
Supply Chain ◽  
Stackelberg Game ◽  
Solution Concept ◽  
Unit Price ◽  
Chain Model ◽  
Screening Process ◽  
Defective Items ◽  
Imperfect Quality ◽  
Theoretical Approaches ◽  
Supply Chain Model

This paper studies supply chain model for imperfect quality items under which unit price and unit marketing expenditure imposed by the buyer, regulates the demand of the item. It is presumed that with the accustomed supply chain model, all produced items are of good quality, coincidentally, it engrosses some percentage of defective items. Thus, inspection process becomes essential for the buyer to segregate the defective items, which are then sold at discounted price at the end of the screening process. In this paper, a supply chain model is ensued to substantiate the interaction and democracy of the participants in the supply chain, the buyer and seller, is pitched by non-cooperative and cooperative game theoretical approaches. In the non-cooperative method, the Stackelberg game approach is used in which one player behaves as a leader and another one as a follower. The co-operative game approach is based on a Pareto efficient solution concept, in which both the players work together to enhance their profit. Lastly, to demonstrate the significance of the theory of the paper, numerical examples including sensitivity analysis are presented.

scholarly journals INVENTORY MANAGEMENT THROUGH EXTENDED STAR-RING SUPPLY CHAIN NETWORK

2017 ◽  
Vol 10 (13) ◽  
pp. 199
Author(s):  
Gm Arun Prasath
Keyword(s):  
Supply Chain ◽  
Inventory Management ◽  
Network Topology ◽  
Mathematical Problem ◽  
Vital Role ◽  
Optimum Number ◽  
Supply Chain Network ◽  
Inventory Problem ◽  
Star Network ◽  
Minimum Number

Objectives: The production-distribution inventory problem has two main sectors namely production and distribution. In this paper, the nonlinearmathematical model of extended star-ring supply chain network is developed.Methods: Planning a distribution network plays a vital role in minimizing the total expenditure of the project; to prove this, a ring network topology is taken to supply goods to the SWs and extended star network topology to supply goods to the selling stores. However, setting up separate SWs for each and every selling store will be highly expensive. Hence, keeping the minimum number of SWs is very important. Selection of SWs from the available SWs is done by replacing diverse values based on the distance limitation.Results: The suggested model is validated with the mathematical problem, and the optimum set of SWs is identified from the result. The result has been substantiated using analytic hierarchy process. Conclusion: The system of optimum number of SWs is obtained from the result. 

scholarly journals Inventory control in a two-level supply chain with learning, quality and inspection errors

2021 ◽  
Author(s):  
Mehmood Khan
Keyword(s):  
Supply Chain ◽  
Product Quality ◽  
Inventory Management ◽  
Human Error ◽  
Threshold Value ◽  
Process Quality ◽  
Lot Size ◽  
Defective Items ◽  
Inspection Errors ◽  
Screening Cost

A common measure of quality for a buyer or a vendor is the defect rate. Defects may represent an attribute, a dimension or a quantity. They may be classified as product quality defects or process quality defects. Product quality defects may be caused by human error which can de due to fatigue, lack of proper training, or other reasons. For example, an inspector may misclassify a defective fuel tank of a car as good. On the other hand, process quality defects maybe caused by a machine going out-of-control. While many researchers assume that the screening processes which separate the defective items are error-free, it would be realistic to consider misclassification errors in this process. Beside inspection errors, learning is another human factor that brings in enhancement in the overall performance of a supply chain. Learning is inherent when there are workers involved in a repetitive type of production process. Learning and forgetting are even more important in manufacturing environments that emphasize on flexibility where workers are cross-trained to do different tasks and where products have a short life cycle. Inventory management with learning in quality, inspection and processing time will be the focus of this thesis. A number of models will be developed for a buyer and/or a two level supply chain to incorporate these human factors. The key findings of this work may be summarized as 1. Inspection errors significantly affect the annual profit. 2. An increase in the unit screening cost reduces the annual profit to a great extent at slower rates of learning. 3. For the two-level supply chain we investigated, learning in production drops the annual cost significantly while the learning in supplier's quality results in a situation where there are no defectives from the suppliers. 4. Type II error may seem to be beneficial for a two level supply chain as the order/lot size goes down and thus affects the costs of ordering, production and screening. 5. Consignment stocking policy performs better than conventional stocking when holding costs go higher than a threshold value.

Operational challenges during a pandemic: an investigation in the electronics industry

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sanjoy Kumar Paul ◽  
Priyabrata Chowdhury ◽  
Md. Tarek Chowdhury ◽  
Ripon Kumar Chakrabortty ◽  
Md. Abdul Moktadir
Keyword(s):  
Supply Chain ◽  
Supply Chains ◽  
Inventory Management ◽  
Demand Management ◽  
Electronics Industry ◽  
Content Type ◽  
Holding Costs ◽  
Inventory Holding ◽  
Practical Implications

PurposeThe recent coronavirus disease 2019 (COVID-19) pandemic poses numerous challenges to supply chains. This pandemic is quite unique when compared to previous epidemic disruptions and has had a severe impact on supply chains. As a result, the operational challenges (OCs) caused by COVID-19 are still unknown among practitioners and academics. It is critical to comprehensively document current OCs so that firms can plan and implement strategies to overcome them. Consequently, this study systematically identifies and ranks COVID-19-related OCs.Design/methodology/approachThis study uses an integrated methodology combining expert interviews and the best-worst method (BWM) to analyze the results. The data have been collected from the electronics industry of Bangladesh, an emerging economy. This study also conducts a sensitivity analysis to check the robustness of the results.FindingsThe results reveal 23 COVID-19-related OCs under five categories: sourcing, production and inventory management, demand management and distribution, return management and after-sales service, and supply chain-wide challenges. The quantitative investigation reveals that overstock in finished goods inventory, low end-customer demands, order cancellations from dealers and retailers, high inventory holding costs and lack of transportation are the top five OCs.Practical implicationsThe findings will help practitioners to understand the OCs and allow them to prepare for future major disruptions and formulate long-term strategies for operations during and after the COVID-19 pandemic.Originality/valueThis study contributes to the literature on supply chain complexity and challenges by considering a major pandemic outbreak. Moreover, the study also contributes to the knowledge on emerging economies, which have been largely neglected in the current literature.

Inventory optimization considering the vehicle capacity and specifics of cash flows at rental storage sites

2020 ◽  
pp. 77-90
Author(s):  
V.D. Gerami ◽  
I.G. Shidlovskii
Keyword(s):  
Supply Chain ◽  
Inventory Management ◽  
Sufficient Conditions ◽  
Cash Flows ◽  
Management Systems ◽  
Cargo Capacity ◽  
Special Modification ◽  
The Cost ◽  
Necessary And Sufficient ◽  
Vehicle Capacity

The article presents a special modification of the EOQ formula and its application to the accounting of the cargo capacity factor for the relevant procedures for optimizing deliveries when renting storage facilities. The specified development will allow managers to take into account the following process specifics in the format of a simulated supply chain when managing inventory. First of all, it will allow considering the most important factor of cargo capacity when optimizing stocks. Moreover, this formula will make it possible to find the optimal strategy for the supply of goods if, also, it is necessary to take into account the combined effect of several factors necessary for practice, which will undoubtedly affect decision-making procedures. Here we are talking about the need for additional consideration of the following essential attributes of the simulated cash flow of the supply chain: 1) time value of money; 2) deferral of payment of the cost of the order; 3) pre-agreed allowable delays in the receipt of revenue from goods sold. Developed analysis and optimization procedures have been implemented to models of this type that are interesting and important for a business. This — inventory management systems, the format of which is related to the special concept of efficient supply. We are talking about models where the presence of the specified delays for the outgoing cash flows allows you to pay for the order and the corresponding costs of the supply chain from the corresponding revenue on the re-order interval. Accordingly, the necessary and sufficient conditions are established based on which managers will be able to identify models of the specified type. The purpose of the article is to draw the attention of managers to real opportunities to improve the efficiency of inventory management systems by taking into account these factors for a simulated supply chain.

A systematic literature review of healthcare supply chain and implications of future research

2019 ◽  
Vol 13 (4) ◽  
pp. 405-435 ◽  
Author(s):  
Anuj Dixit ◽  
Srikanta Routroy ◽  
Sunil Kumar Dubey
Keyword(s):  
Supply Chain ◽  
Literature Review ◽  
Inventory Management ◽  
Cold Chain ◽  
Future Research ◽  
Research Papers ◽  
Content Type ◽  
Drug Manufacturing ◽  
Customer Training

Purpose This paper aims to review the healthcare supply chain (HSC) literature along various areas and to find out the gap in it. Design/methodology/approach In total, 143 research papers were reviewed during 1996-2017. A critical review was carried out in various dimensions such as research methodologies/data collection method (empirical, case study and literature review) and inquiry mode of research methodology (qualitative, quantitative and mixed), country-specific, targeted area, research aim and year of publication. Findings Supply chain (SC) operations, performance measurement, inventory management, lean and agile operation, and use of information technology were well studied and analyzed, however, employee and customer training, tracking and visibility of medicines, cold chain management, human resource practices, risk management and waste management are felt to be important areas but not much attention were made in this direction. Research limitations/implications Mainly drug and vaccine SC were considered in current study of HSC while SC along healthcare equipment and machine, hospitality and drug manufacturing related papers were excluded in this study. Practical implications This literature review has recognized and analyzed various issues relevant to HSC and shows the direction for future research to develop an efficient and effective HSC. Originality/value The insight of various aspects of HSC was explored in general for better and deeper understanding of it for designing of an efficient and competent HSC. The outcomes of the study may form a basis to decide direction of future research.

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