Inventory Management Model Research Articles

An equity-oriented multi-objective inventory management model for blood banks considering the patient condition: A real-life case

The absence of systematic disparities in health utilization leads to achieving equity in health. However, equity in delivering healthcare services is always challenging because of financial and medical resource constraints. In this regard, a practical multi-objective mixed-integer linear programming model with priority-differentiated demand classes is presented for cost-effective inventory management of blood products considering health equity. The system deals with multiple substitutable products. There are elective and non-elective demands, which are categorized into three main classes based on medical urgencies. The health objectives are investigated to achieve a desirable health equity level in delivering healthcare services to patients. Moreover, the economic objective is pursued to minimize total costs incurred across managing the inventory without weakening the service level. An effective demand-oriented hybrid heuristic is proposed to issue and allocate the blood for demand satisfaction equitably. A goal programming approach is utilized to find the optimum solution. The applicability of the model is validated through a real case study. Finally, several sensitivity analyses are conducted to gain useful managerial insights. According to the results, the proposed model presents a proper solution by making a reasonable health-economic trade-off. Also, the results illustrate the beneficial improvement in patient care and promoting health equity.

Seasonal Inventory Management Model for Raw Materials in Steel Industry

We developed a seasonal inventory management model for raw materials, such as iron ore and coal, for multiple suppliers and multiple mills. The Nippon Steel Corporation imports more than 100 million tons of raw material annually by vessels from Australia, Brazil, Canada, and other countries. Once these raw materials arrive in Japan, they are transported to domestic mills and stored in yards before being treated in a blast furnace. A critical problem currently facing the industry is the limited capacity of the yards, which leads to high demurrage costs while ships wait for space to open up in the yards before they can unload. To reduce the demurrage costs, the inventory levels of the raw materials must be kept as low as possible. However, inventory levels that are too low may lead to inventory shortage resulting from seasonal supply disruptions (e.g., a cyclone in Australia) that delay the supply of raw materials. Because both excess and depleted inventory levels lead to increased costs, optimal inventory levels must be determined. To solve this problem, we developed an inventory management model that considers variations on the supply side, differences that should be observable upon looking at the ship operations. The concept is to model the probability distribution of ship arrival intervals by brand groups and mills. We divided ship operations into two stages: arrival at all mills (in Japan) and arrival at individual mills. We modeled the former as a nonhomogeneous Poisson process and the latter as a nonhomogeneous Gamma process. Our proposed model enables inventory levels to be reduced by 14% in summer and 6% in winter.

A Multi-Objective Model for Inventory Management of the Integrated Multi-Product Supply Chain Considering Central Warehouse and Potential Demand

In this research, an inventory management model is developed by the seller for a three-echelon supply chain, which also includes a central warehouse, along with order constraints. In this method, the seller monitors the level of inventory of the retailer so that it determines the time and amount of products for the seller and the retailer and reduces the inventory costs for the seller and the retailer. Sales inventory management in the supply chain has an integrated approach to planning and controlling materials and information in the production and distribution chain, transportation, warehouses and customers. One of the objectives of the proposed mathematical model is to determine the inventory of retailers, vendors, central warehouse and the optimal refund rate for the seller and central warehouse, which ultimately leads to a reduction in the cost of the entire system. In this study, after presenting a three-objective mathematical model to study the three-level supply chain by considering several retailers and multiple vendors and the central warehouse, the model is solved using GAMS software by the Epsilon constraint method and to test. The validation of the proposed model is examined by providing an example of the proposed model.

Reducing Food Waste in the Retail Supply Chains by Improving Efficiency of Logistics Operations

One of the basic problems of sustainability in modern society is the reduction of waste, particularly when it comes to food. Food waste has negative impacts on different dimensions of sustainability: social (hunger), economic (resource costs), and environmental (resource consumption and waste generation). This paper focuses on waste reduction through improving the inventory management system in the dairy distribution chain by the application of modern information and communication technologies (ICT). The approach is tested and verified in a case study by application of simulation modelling. Two inventory management models are created, and their impact on waste in the distribution part of the supply chain is examined. Model 1 represents the current dairy inventory management system in the supply of retail stores. Model 2 is based on a higher level of information connectivity between participants (RFID product labelling and the appropriate level of information technology), enabling automatic product ordering and changes in inventory management policy. The obtained results confirm that coordinated inventory management, supported by the application of modern ICT, can significantly contribute to the improvement of the sustainability of the food supply chain, and provide an exact quantification of the given contribution in the case of the dairy industry.

Inventory Management and Financial Performance of Private Hospitals: A Positivist Evidence from Western Uganda

Purpose: This study set out to empirically examine the relationship between inventory management and private hospitals' financial performance in Western Uganda.
 Methodology: The study adopted a positivist approach and a cross-sectional research design to collect data from 32 Private hospitals in Western Uganda. The study used a closed-ended questionnaire to collect data and simple linear regression for data analysis.
 Findings: Results revealed inventory management as a significant predictor of private hospitals' financial performance in Western Uganda. The study recommended that private hospitals adopt robust and scientific inventory management systems and models that aim to optimise stock levels and minimise costs if they are to achieve substantial financial performance.
 Contribution to Practice and Policy: The study has deep-rooted the urgent need for private hospitals to adopt more stringent inventory management systems that will ensure adequate stock levels, minimise costs and enhance superior financial performance. However, the study was positivistic, thus subject to methods bias that could have affected the results' validity.

Research of material and technical resources inventory management in projects supply chains

The object of research is the processes of material and technical support of projects in the field of supply chain management. One of the most challenging areas faced by logistics and project managers is determining the appropriate level of supply chain inventory management when implementing projects. Today, there is a demand for the development and implementation of dynamic supply chains, the essence of which is to increase the service level by increasing the speed of response to customer requests and flexibility in excess components (high stock levels, unbalanced duration of supply cycles), taking into account the uncertainty of demand.The analysis of the justification of the value of the supply chain, namely of such components as logistics costs, the cost of storing inventories and deficit costs, is carried out. Models of inventory management in the supply chain with centralized and decentralized service are presented. Calculations of the indicators of the standard deviation of demand and the duration of the supply cycle, the values of the cyclic and safety stock are presented. For the situation of centralized service of the resource flow, the influence of the demand dependence on the stock level was investigated.The study used the theory of supply chain management and project management, which made it possible to take into account the variability of demand and the duration of supply. As a result of the work, models of the volume of insurance stocks in conditions of uncertainty in demand and the duration of the supply cycle of resources are proposed. In order to ensure the optimal strategy of resource provision, the concept of «service level» was investigated. The service level of the first kind (cyclical service level) and the service level of the second kind (saturated demand) are considered.The results of this research provide an opportunity to improve project efficiency in the face of volatile demand, reduced product life cycle and increased competition. Such changes require supply chains to develop strategies that are focused on the end user, that is, an integrated supply chain management strategy is required.

Optimisation of accounting model of inventory management in the textile industry

The supply system consists of several elements, which in their characteristics are distinguished in the overall structure of the supply system. They are defined uniquely in accordance with the function they perform, and in reality they appear at all levels of the budget system organization. Functioning of the supply system is possible only with the existence of certain inventories or reserves of material assets. The stocks represent the prescribed and determined quantities of material assets stored in the warehouses in order to ensure the normal functioning of the institutions. Using the supplies management accounting model in textile industry is providing a continuous provision of equipment. This is essential to reach the adequate level of competence, which is in line with autonomous budget financing companies. Taking into account the specificity of the institutions, with an emphasis on the quality of the equipment, there is also the possibility for savings in maintaining them. The aim of this paper is to present how the inventory management accounting system can optimize costs in the textile industry due to the full satisfaction of the optimal supply criterion.

ECONOMIC AND MATHEMATICAL MODELING AND INFORMATION TECHNOLOGIES IN MARKETING AUDIT

The article is devoted to determining the role of economic and mathematical modeling and information technologies in conducting a marketing audit. The importance of a relatively new direction in marketing science – marketing audit – is emphasized. The main areas and directions of its implementation, in particular the audit of marketing environment, strategy, systems, products, as well as marketing functions – goods, prices, advertising, sales promotion, product promotion, sales staff – are identified. Emphasis is placed on key methods of marketing audit, in particular general scientific, general economic, marketing ones, and the directions of their use are determined. The importance of mathematical and statistical methods in making management decisions and solving marketing problems is noted. The main methods that play a key role in solving the tasks of marketing audit, in particular correlation-regression, dispersion, variational, discriminant, factor, cluster analysis methods, are named. It is noted that balance sheet, optimization, network planning methods, inventory management models, demand and consumption modeling, queuing theory, game theory, decision making in the conditions of uncertainty and risk are the main economic and mathematical models in marketing.
 It is emphasized that information technologies are a key tool in conducting a marketing audit. Modern capabilities of computer technology create the conditions for accurate, high-quality, timely information and provide its high-quality, scientifically sound processing. It is noted that information technologies provide the development and implementation of management decisions. It is substantiated that with the help of information technologies the access of audit specialists to the data and knowledge bases necessary for the analysis, as well as for the implementation of economic and mathematical models, without which it is impossible to imagine a modern marketing audit, is open. It is stated that information technologies have also become a key means of communication, transmission of information, holding operational business meetings and conferences.

THE FORMATION AND EFFECTIVE USE OF INVENTORIES BY ENTERPRISES

The article considers the issues of formation and effective use of inventories by enterprises. It is confirmed that the subject of the inventory management policy consists of two main blocks: the inventory formation policy and the inventory use management policy. Inventory formation management occurs by applying inventory management models. Inventory use management performed by means of indicator calculations of reserves effective use. Inventories are grouped and classified according to the most important features. Inventory management tasks and exiting models is carried out, which takes into account the classic and modern approach to doing business. It is proved that the concepts previously used fail to justify themselves in the new conditions. It is established that most companies in the world improve the efficiency of inventory management as follows: rationalization of processes between companies, shifting ownership of inventory towards suppliers (implementation of the principle of “inventory managed by supplier”), direct delivery of finished products to the consumer in accordance with his wishes and financial capabilities, inventory management using the principle of “just in time”, introduction of flexible (lean) production, etc. Thus, the main trend of foreign firms, in contrast to domestic ones, is the spread of the concept of inventory minimization. Nine provisions (theses) have been formulated for the methodology of forming various for managing inventory values of an enterprise.

Dynamics Analysis and Fractional-Order Approximate Entropy of Nonlinear Inventory Management Systems

Inventory management is complex nonlinear systems that are affected by various external factors, including course human action and policy. We study the inventory management model under special circumstances and analyse the equilibrium point of the system. The dynamics of the system is analysed by means of the eigenvalue trajectory, bifurcations, chaotic attractor, and largest Lyapunov exponent diagram. At the same time, according to the definition of fractional calculus, the fractional approximate entropy is used to analyse the system, and the results are consistent with those of the largest Lyapunov exponent diagram, which shows the effectiveness of this method.

Distribution network planning and inventory management in a multi-retailing supply chain

A In this paper, we are aimed at discussing problems of distribution network planning and inventory management in a multiple-retailing supply chain. We study the distribution model and inventory management model, integrating both models to analyse the optimal decisions on maximum profit. The main methodology we used is literature study and model formulations. Through the research, we finally present the optimal distribution and inventory decision.

APPLICATION OF PERIODIC REVIEW INVENTORIES MODEL IN A TYPICAL MEXICAN FOOD COMPANY

The Mexican family companies must face the challenges of market volatility with greater recurrence, forcing them to use effective tools and models for the proper management of their organizations and inherent activities, such as inventory management. Therefore, this research was carried out at “Moles Santa Monica”, a typical food company located in the city of Puebla, Mexico. This enterprise has reflected a high variability in the administration of its inventories, with a Coefficient of Variation (CV) greater than 0.2 in most of their portfolio products. In this way, the objective of this study was to propose an inventory management model that might reduce the shortages and overstock, and also; improves its performance and profitability when it is managed. The applied methods were Pareto and ABC model to choose correctly the best seller company products. The inventory management model chosen was the periodic review (R, S) as well, for being the most effective and the one that best suited the circumstances of the company in question. Three of the portfolio products were studied (MPP10, MPC10 and COP10) due to they are the most representative in incomes and valuables for the company managers. The results allowed us to propose the review periodic model (R), the optimal quantity of units to produce (Q), the safety stock (Ss) and the maximum inventory (S) for each product. We conclude that this model will help the company to face the uncertainty of the demand. Finally, we include limitations and future studies.

A Continuous Review Production-Inventory System with a Variable Preparation Time in a Fuzzy Random Environment

With the increase in the varieties products and the increasing uncertainty about product demand, the production preparation time is a significant factor in addressing these issues. The trade-off between the reduction of the production preparation time and the associated cost remains a critical decision. With this backdrop, this study presents a continuous review production-inventory model with a variable production preparation time and a time-dependent setup cost. The demand during the preparation time is captured through a min-max distribution-free approach. In a stochastic framework, the order quantity, reorder point, and setup time are optimized by minimizing the expected cost considering the time-value effect. Further, a fuzzy model is formulated to tackle the imprecise nature of the production setup time and demand. Two algorithms are developed using an analytical approach to obtain the optimal solution. A numerical illustration is given to present the key insights of the model for effective inventory management. It is observed that order quantity and total cost are more sensitive at the lower side of the optimal setup time rather than at the higher side. The discount rate is also found to be a sensitive factor while minimizing the total expected cost.

Optimization of Inventory Management to Prevent Drug Shortages in the Hospital Supply Chain

Drug shortage is always a critical issue of inventory management in healthcare systems since it potentially invokes several negative impacts. In supply chain management, optimization goes hand-in-hand with inventory control to address several issues of the supply, management, and use of drugs. However, it is difficult to determine a shortage situation in a hospital due to multiple unpredictable reasons, such as manufacturing problems, supply and demand issues, and raw material problems. To avoid the shortage problem in a hospital, efficient inventory management is required to operate the system in a sustainable way and maximize the profit of the organization in the Hospital Supply Chain (HSC). In this work, we study a drug refilling optimization problem, a general model for drug inventory management in a hospital. We then investigate a Deep Reinforcement Learning (DRL) model to address this problem under an online solution that can automatically make a drug refilling decision in order to prevent a drug shortage. We further present a numerical result to verify the performance of the proposed algorithm, which outperforms the baselines (e.g., over-provisioning, ski-rental, and max-min) in terms of the refilling cost and the shortage rate.

Inventory management in blood supply chain considering fuzzy supply/demand uncertainties and lateral transshipment

Supply and demand uncertainties combined with very short lifetime of blood platelets has led to significant wastage of the total blood collected from the donors. Conversely, great shortage of platelets may be obtained due to the limited number of donors and emergency demands. Therefore, it is of utmost importance to develop appropriate inventory management model to simultaneously minimize both shortage and wastage along the blood supply chain. To achieve this purpose, this paper presents an Inventory Management model for Age-differentiated platelets under supply/demand Uncertainties (IMAU) for Blood Supply Chains with Lateral Transshipment (BSCLT), resulting a new model named IMAU-BSCLT. The proposed model is solved using whale optimization algorithm considering the costs of ordering from blood centers and lateral transshipment, transportation, inventory holding, shortage, and wastage. In order to validate the proposed methodology, a case study of blood supply chain is used to show the usability of the proposed model and claim its benefits over existing models. Simulation results demonstrate that lateral transshipment between different demand nodes has a major impact on load balancing leads to simultaneously reduce both shortage and wastage costs. According to the obtained results, shortage rate (total shortage per total demands) and wastage rate (total wastage per total supply) of the proposed method are 3.4 % and 4.8 %, respectively.

A robust multi-objective optimization model for inventory and production management with environmental and social consideration: A real case of dairy industry

Every day, an abundance of perishable materials and products are transferred from suppliers to producers, as well as from producers to retailers. In the meantime, operating costs, transportation costs, and environmental impacts enhance due to the limited lifespan of dairy products, time constraints, limited inventory to hold, and high frequency of transportation. This paper is about designing a three-level sustainable dairy supply chain under uncertain conditions. In this study, a multi-objective model is proposed to minimize the total costs and environmental impacts, and maximize the social impacts of a multi-period and multi-product chain composed of suppliers, producers, and retailers, which is applied to a dairy company. The delivery time and the first-in, first-out (FIFO) policy of the products are of particular importance in the proposed model. Moreover, a robust optimization approach is applied to consider the uncertainty associated with demand, transportation costs, production costs, holding costs, and facilities’ capacity. To solve the proposed model, a hybrid method based on a heuristic algorithm, and the augmented ε-constraint method is developed. Based on the results, economic costs and environmental impacts decreased by 18.5% and 25%, respectively. The conclusions indicate the efficiency and applicability of the proposed model and also show that the developed algorithm can attain high-quality solutions in a reasonable time.

Application of Medical Material Inventory Model Under Deep Learning in Supply Planning of Public Emergency

The purposes are to solve inventory management problems in emergencies, optimize inventory management structure, and improve management efficiency. The medical material inventory management is taken as the research object. According to previous research, the existing material management model has problems such as management confusion, resource waste, and insufficient data analysis. Hence, the strengths of deep learning algorithms are utilized to address the above problems. A deep learning-based medical material inventory management model is constructed through the reasonable classification of material management methods. This model effectively utilizes the data by analyzing disaster data in different regions and establishes a corresponding inventory management model according to the classification standards. The numerical analysis of three examples further verifies the effectiveness of the proposed model. On this basis, the model is compared with the latest inventory management models to further determine its advantages. Results suggest that the medical supplies management model based on deep learning can interpret and analyze the data well and calculate the optimal inventory and management method of the model with limited funds based on the data. Compared with the latest inventory management models, the proposed model can provide a prediction accuracy as high as 92.45%. Under the same data, the analysis time of the medical material management method based on deep learning is only 35 minutes, which has undeniable advantages compared with other models. The proposed model can provide research ideas for material management in emergencies.

Optimization of the system of management of stores of the car service with the help of imitation simulation

The purpose of simulation is described, the theoretical foundations of the simulation model of inventory management at the service station with its scheme are given. The criterial function of delays, which is the main one in the management of stocks at the service station, is given, the analysis of the influence of the controlled parameters of the model on the criterial function is carried out. The algorithm of search optimization with integration into the simulation model is resulted and optimal parameters of the stock level

The static model of inventory management without a deficit with Neutrosophic logic

In this paper, we present an expansion of one of the well-known classical inventory management models, which is the static model of inventory management without a deficit and for a single substance, based on the neutrosophic logic, where we provide through this study a basis for dealing with all data, whether specific or undefined in the field of inventory management, as it provides safe environment to manage inventory without running into deficit , and give us an approximate ideal volume of inventory. Since the ideal size is affected by the rate of demand for inventory, we present in this paper a study of the rate of demand for inventory when it is not precisely defined, and we find that the indeterminate values ​​of the demand rate cannot be ignored, because they actually affect determining the ideal size of inventory and calculating its costs, thus affecting on the efficiency of the facility and achieve great profits for it.

Logistics of essential oil production

The purpose of this article was to investigate and justify the need for the introduction of logistics management in the essential oil production industry. We have identified the main problems of using logistics by economic (business) entities. Specific characteristics that must be taken into account when implementing logistic management into essential oil production were analyzed. The main logistic tasks of economic (business) entities involved in the process of essential oil production have been described. Furthermore, we offer a one-product deterministic model of inventory management that is the basis for making economically sound logistics decisions when managing resources of essential oil production.