scholarly journals Impact of Trapezoidal Demand and Deteriorating Preventing Technology in an Inventory Model in Interval Uncertainty under Backlogging Situation

Mathematics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 78
Author(s):  
Rajan Mondal ◽  
Ali Akbar Shaikh ◽  
Asoke Kumar Bhunia ◽  
Ibrahim M. Hezam ◽  
Ripon K. Chakrabortty
Keyword(s):  
Inventory Management ◽  
Optimization Problem ◽  
Mathematical Formulation ◽  
Optimal Solution ◽  
Inventory Model ◽  
Interval Uncertainty ◽  
Swarm Optimization ◽  
Preservation Technology ◽  
Proposed Model ◽  
The Impact

The demand for a product is one of the important components of inventory management. In most cases, it is not constant; it may vary from time to time depending upon several factors which cannot be ignored. For any seasonal product, it is observed that at the beginning of the season, demand escalates over time, then it is stable and after that, it decreases. This type of demand is known as the trapezoidal type. Also, due to the uncertainty of customers’ behavior, inventory parameters are not always fixed. Combining these two concepts together, an inventory model is formulated for decaying items in an interval environment. Preservative technology is incorporated to preserve the product from deterioration. The corresponding mathematical formulation is derived in such a way that the profit of the inventory system is maximized. Consequently, the corresponding optimization problem is converted into an interval optimization problem. To solve the same, different variants of quantum-behaved particle swarm optimization (QPSO) techniques are employed to determine the duration of stock-in time and preservation technology cost. To illustrate and also to validate the model, three numerical examples are considered and solved. Then the computational results are compared. Thereafter, to study the impact of different parameters of the proposed model on the best found (optimal or very close to optimal) solution, sensitivity analysis are performed graphically.

An (s, S) Inventory Optimization Problem

2019 ◽  
pp. 187-206
Author(s):  
Gizem Sağol ◽  
Görkem Sariyer ◽  
Banu Yetkin Ekren ◽  
Mustafa Gökalp Ataman
Keyword(s):  
Inventory Management ◽  
Optimization Problem ◽  
Service Level ◽  
Inventory Model ◽  
Considerable Effort ◽  
Medical Products ◽  
High Service ◽  
Inventory Optimization ◽  
Medical Supplies

Inventory management is one essential lever to use the resources efficiently. However, managing inventories in hospitals is a challenging task because of the several issues: a high service level of medical supplies is required under the unpredictable demand, medical products constitute a significant portion of the overall costs, and the management of these supplies requires considerable effort to check the levels to track usage and to distribute them. Therefore, it is pertinence to apply operations research tools to cope with the managerial issues of the hospital inventory system. In this chapter, the authors implement an (s, S) inventory model by using simulation in a case study of a hospital in Izmir, Turkey. They aim to analyze the unpredictable nature of demand of medical supplies in this hospital and its implications on the developed inventory policy.

Dual Approach to the Harmonized Model between Inventory Reduction and Heijunka (Production Leveling) based on the Minimum Average-energy Principle

2019 ◽  
Vol 01 (02) ◽  
Author(s):  
Tsuyoshi Kurihara ◽  
Takaaki Kawanaka ◽  
Hiroshi Yamashita
Keyword(s):  
Production Planning ◽  
Inventory Management ◽  
Average Energy ◽  
Optimal Solution ◽  
Exponential Smoothing ◽  
Aggregate Production Planning ◽  
Energy Principle ◽  
Dual Approach ◽  
Aggregate Production ◽  
Proposed Model

A major issue in manufacturing is the balance between inventory reduction and heijunka (i.e., production leveling). To address this issue in aggregate production planning, linear programming models that consider many factors and use “exponential smoothing” as an approximate leveling method have been mainly studied. However, this methodology has problems that may limit its use as an optimal solution approximate method, and impair the timeliness required for aggregate production planning by the complexity of these models. To solve this issue, we have been developing harmonized models to balance between lowering the inventory management energy and increasing the heijunka entropy, based on demand and inventory quantities as simple optimization models. In this study, we develop a dual approach to the previously proposed model to maximize the heijunka entropy and propose a new model to minimize the inventory management energy based on the “minimum average-energy principle.” We show that the proposed model’s inventory state is lower than that of traditional exponential smoothing through numerical experiments. This study, therefore, theoretically enables a new optimal solution to the harmonized (balancing) problem, based on the concept of entropy and energy, and practically enables aggregate production planning in a timely and simple manner.

scholarly journals Retailer’s Joint Ordering, Pricing, and Preservation Technology Investment Policies for a Deteriorating Item under Permissible Delay in Payments

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Umakanta Mishra ◽  
Jacobo Tijerina-Aguilera ◽  
Sunil Tiwari ◽  
Leopoldo Eduardo Cárdenas-Barrón
Keyword(s):  
Trade Credit ◽  
Optimal Solution ◽  
Inventory Model ◽  
Selling Price ◽  
Permissible Delay In Payments ◽  
Investment Policies ◽  
Technology Investment ◽  
Preservation Technology ◽  
Preservation Technology Investment ◽  
Delay In Payments

This article develops an inventory model for deteriorating items with controllable deterioration rate (by using preservation technology) under trade credit policy. As in practical scenarios the demand of an item is directly associated with its selling price, keeping this in mind, it is assumed to be a price dependent demand. The main objective of the inventory model is to determine jointly the optimal ordering, pricing, and preservation technology investment policies for retailer so that the total profit is maximized. The effects of key parameters on optimal solution are studied through a sensitivity analysis with the aim of examining the behavior of the inventory model with controllable deterioration under the permissible delay in payments.

scholarly journals An Inventory Model based on Manufacturer-Direct Business Model with the help of E-Commerce Trading Strategies

2019 ◽  
Vol 8 (6S4) ◽  
pp. 507-512
Keyword(s):  
Inventory Management ◽  
Business Model ◽  
Customer Relations ◽  
Inventory Model ◽  
Trading Strategies ◽  
Waste Generation ◽  
Model Based ◽  
Operation Costs ◽  
Proposed Model ◽  
Production And Operation

The significance of inventory management partake in the rapid growth and development of all organizations. Inventories impacts sales and revenues, customer relations, production and operation costs etc. On the other hand, online shopping became a trendy choice among the web-users, they can buy any product either through online market places or over web stores. The main intention of this paper is to develop an inventory model based on 'Manufacturer-direct' business model with the help of e-commerce trading strategies. Also this proposed model considered the process of recycling and disposal of deteriorating items over 3R approach . In order to maximize the profits and to minimize the waste generation, this model provides optimum values. Numerical examples are illustrated to validate the model.

scholarly journals Hybrid method for achieving Pareto front on economic emission dispatch

2020 ◽  
Vol 10 (4) ◽  
pp. 3358
Author(s):  
Kummari Rajesh ◽  
N. Visali
Keyword(s):  
Genetic Algorithm ◽  
Particle Swarm Optimization ◽  
Differential Evolution ◽  
Hybrid Method ◽  
Optimization Problem ◽  
Particle Swarm ◽  
Optimal Solution ◽  
Test System ◽  
Swarm Optimization ◽  
Metaheuristic Methods

In this paper hybrid method, Modified Nondominated Sorted Genetic Algorithm (MNSGA-II) and Modified Population Variant Differential Evolution(MPVDE) have been placed in effect in achieving the best optimal solution of Multiobjective economic emission load dispatch optimization problem. In this technique latter, one is used to enforce the assigned percent of the population and the remaining with the former one. To overcome the premature convergence in an optimization problem diversity preserving operator is employed, from the tradeoff curve the best optimal solution is predicted using fuzzy set theory. This methodology validated on IEEE 30 bus test system with six generators, IEEE 118 bus test system with fourteen generators and with a forty generators test system. The solutions are dissimilitude with the existing metaheuristic methods like Strength Pareto Evolutionary Algorithm-II, Multiobjective differential evolution, Multi-objective Particle Swarm optimization, Fuzzy clustering particle swarm optimization, Nondominated sorting genetic algorithm-II.

scholarly journals Integrated multistage supply chain inventory model of multiple retailers with imperfect production and inspection systems

2021 ◽  
Author(s):  
Chi-Jie Lu ◽  
Ming Gu ◽  
Tian-Shyug Lee ◽  
Chih-Te Yang
Keyword(s):  
Supply Chain ◽  
Optimal Solution ◽  
Solution Procedure ◽  
Inventory Model ◽  
Model Complexity ◽  
Supply Chain System ◽  
Imperfect Production ◽  
Proposed Model ◽  
Inspection Systems ◽  
Total Profit

Abstract An integrated multistage supply chain inventory model containing a single manufacturer and multiple retailers is proposed to consider deteriorating materials and finished products with imperfect production and inspection systems. The main purpose is to jointly determine the manufacturer’s production and delivery strategies and the retailers’ replenishment strategies to maximize the integrated total profit. First, the individual total profit functions of the manufacturer and multiple retailers are established and are integrated to form the total profit function of the supply chain system. Then, to address the model complexity, an algorithm is proposed to obtain the optimal solution. Several practical numerical examples are presented to demonstrate the solution procedure, and a sensitivity analysis is performed on the major parameters. From the numerical results, several findings that differ from those in the previous literature were observed. First, retailers with larger market scale, better cost control, and inspection capabilities guarantee higher integrated total profit. Second, increasing the deterioration rates of materials and finished products affect the order quantity of materials in various ways. Third, the manufacturer’s shipping strategy is rigid and not easily adjusted in the proposed model. The performance of the proposed model has several meaningful management implications.

scholarly journals Blood platelet bank inventory management: an approximate dynamic programming approach

2021 ◽  
Author(s):  
Usama S. Albdulwahab
Keyword(s):  
Inventory Management ◽  
Blood Platelets ◽  
Blood Platelet ◽  
Inventory Model ◽  
Blood Bank ◽  
Artificial Blood ◽  
Blood Types ◽  
Proposed Model ◽  
Supply Model ◽  
Right To Refuse

Blood platelets are precious and highly perishable; their supply and demand suffer from significant variation. Consequently, the inventory management of platelets is an actual, contemporary prob- lem of considerable human interest. Although many researchers have solved a plethora of inventory models, their solutions have faced various challenges. This dissertation models some of these chal- lenges, alongside expenses and stock levels. This dissertation is based on four key objectives: (1) to develop a blood platelet inventory model that can represent an actual blood bank inventory, while overcoming the problem's curse of dimensionality; (2) to look for the best issuing policy based on the proposed model that can serve different incoming blood platelet demands; (3) to analyze the effect of having a new, artificial blood platelet alongside the existing natural eight blood types; and (4) to enhance the proposed model for a dual-supplied regional blood platelet bank that serves a network of hospitals. Blood platelet inventory management model is a multi-period, multi-product model that considers the eight natural blood types with uncertain demand, and deterministic lead times, alongside the artificial platelet and patients right to refuse it. The study is supported by both a review of literature and a testing data provided by the Canadian Blood Service. The findings show that modeling blood platelet inventory management, including the eight blood types and their ages, represents the actual-life model without any need for downsizing. It also leads to significantly reductions in shortages and outdates while increasing reward gained and maintaining minimal inventory levels. Compared to a single supply model, the dual supply model give less shortage and outdate rates. The regional blood bank inventory model considers the fact that patients have the right to refuse transfusion using artificial blood platelets. Finally, if the percentage of artificial supply in the inventory is more than 30% and the rate of patient acceptance is more than 30%, then both outdate and shortage percentages are below 1%.

A decision model for warranted second-hand products considering upgrade level, past age, preventive maintenance and sales volume

2018 ◽  
Vol 24 (4) ◽  
pp. 544-558
Author(s):  
Mohamed N. Darghouth ◽  
Anis Chelbi
Keyword(s):  
Preventive Maintenance ◽  
Decision Model ◽  
Optimal Solution ◽  
Expected Profit ◽  
Sales Volume ◽  
Content Type ◽  
Effort Level ◽  
Warranty Period ◽  
Proposed Model ◽  
The Impact

Purpose The purpose of this paper is to present a decision model for second-hand products to determine the optimal upgrade level, warranty period and preventive maintenance (PM) effort level which maximize the total expected profit generated by the dealer considering any given past age of the product and the effect of the sales volume. Design/methodology/approach A mathematical model is developed to derive the optimal triplet: upgrade level, warranty period and PM effort level, which maximize the total expected profit generated by the dealer for any second-hand product with a given past age. Numerical experimentations have been conducted to investigate the effectiveness of the proposed model and to explore the interactions among the model variables. Findings Numerical experimentations including a sensitivity analysis have been conducted on the model key parameters. The obtained results show that performing PM actions during the warranty period helps the dealers to provide extended warranty for older second-hand products without spending a significant effort on upgrade actions and therefore increase the volume of sales. Also, the interaction between the PM level and the profit margin threshold is demonstrated. Finally, the effect of the sales volume function parameters (the price and warranty elasticity parameters) on the optimal solution is characterized. Research limitations/implications Given the complexity of the profit function to be maximized involving a considerable number of decision variables with different nature, the authors limited the study to the case where the past age of the second-hand product is known. Practical implications The proposed model aims to provide second-hand product dealers with a modeling framework that enables them to have a realistic estimation of the generated profit by integrating the marketing and engineering key parameters of the second-hand product. Originality/value Most of the existing literature dealing with the reliability improvement of second-hand products does not take into account the fact that a realistic estimation of the total profit generated by the dealer requires the consideration of the sales volume. The latter is closely related to the marketing parameters characterized by the warranty period length and the second-hand product selling price. The proposed model introduces the effect of the total sales volume on the total expected profit. The authors also introduce the concept of discrete upgrade levels for a better control of the restoration degree. The authors study the impact of warranty and price elasticity parameters on the optimal solution and the resultant interaction with the customer purchase decision and consequently the sales volume.

scholarly journals Cooperative Passenger Inflow Control in Urban Mass Transit Network with Constraint on Capacity of Station

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Jianyuan Guo ◽  
Limin Jia ◽  
Yong Qin ◽  
Huijuan Zhou
Keyword(s):  
Particle Swarm Optimization ◽  
Waiting Time ◽  
Optimization Problem ◽  
Optimal Solution ◽  
Mass Transit ◽  
Constrained Optimization Problem ◽  
Swarm Optimization ◽  
Transit Network ◽  
Urban Mass Transit ◽  
Transfer Stations

In urban mass transit network, when passengers’ trip demands exceed capacity of transport, the numbers of passengers accumulating in the original or transfer stations always exceed the safety limitation of those stations. It is necessary to control passenger inflow of stations to assure the safety of stations and the efficiency of passengers. We define time of delay (TD) to evaluate inflow control solutions, which is the sum of waiting time outside of stations caused by inflow control and extra waiting time on platform waiting for next coming train because of insufficient capacity of first coming train. We build a model about cooperative passenger inflow control in the whole network (CPICN) with constraint on capacity of station. The objective of CPICN is to minimize the average time of delay (ATD) and maximum time of delay (MTD). Particle swarm optimization for constrained optimization problem is used to find the optimal solution. The numeral experiments are carried out to prove the feasibility and efficiency of the model proposed in this paper.

Topology Optimization Design of Bars Structure Based on SKO Method

2013 ◽  
Vol 394 ◽  
pp. 515-520 ◽  
Author(s):  
Wen Jun Li ◽  
Qi Cai Zhou ◽  
Xu Hui Zhang ◽  
Xiao Lei Xiong ◽  
Jiong Zhao
Keyword(s):  
Global Optimization ◽  
Topology Optimization ◽  
Optimization Design ◽  
Optimization Problem ◽  
Optimization Problems ◽  
Optimization Methods ◽  
Topology Optimization Problem ◽  
Proposed Model ◽  
Continuum Structure ◽  
The Impact

There are less topology optimization methods for bars structure than those for continuum structure. Bionic intelligent method is a powerful way to solve the topology optimization problems of bars structure since it is of good global optimization capacity and convenient for numerical calculation. This article presents a SKO topology optimization model for bars structure based on SKO (Soft Kill Option) method derived from adaptive growth rules of trees, bones, etc. The model has been applied to solve the topology optimization problem of a space frame. It uses three optimization strategies, which are constant, decreasing and increasing material removed rate. The impact on the optimization processes and results of different strategies are discussed, and the validity of the proposed model is proved.

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