Replenishment of imperfect items in an EOQ inventory model with partial backordering

2020 ◽  
Vol 54 (2) ◽  
pp. 413-434
Author(s):  
Ata Allah Taleizadeh ◽  
Mahboobeh Perak Sari Khanbaglo ◽  
Leopoldo Eduardo Cárdenas-Barrón
Keyword(s):  
Inventory Model ◽  
The Other ◽  
Inventory Level ◽  
Long Distance ◽  
Numerical Example ◽  
Shortage Cost ◽  
Partial Backordering ◽  
Imperfect Items ◽  
Optimal Value ◽  
Period Duration

This paper deals with an inventory model in which a percent of the items in the lot is imperfect. The supplier is far from the buyer. After the reception of the order, immediately the products are inspected and imperfect items are identified. Due to the fact that supplier is located at long distance and the demand is needed to cover, the imperfect items are replenished by perfect ones from a local supplier at higher cost. In addition, the imperfect items are withdrawn and sold at a salvaged price as second-degree items. The shortage is allowed and partially backordered. The following three cases are considered: Case I. The reordered items are received when inventory level is zero; Case II. The reordered items are received when the backordered quantity is equal to the imperfect items quantity; and Case III. The reordered items are received when shortage is still remained. These cases are studied and analyzed in detail. In each case, the aim is to obtain the optimal value of the length period and the percent of period duration in which the inventory level is positive. A numerical example is presented to show the applicability of proposed inventory model. The results show that Case I has the lowest holding and shortage cost, so the total benefit is higher than the other two cases.

scholarly journals An Inventory Model for Imperfect Quality Products with Rework, Distinct Holding Costs, and Nonlinear Demand Dependent on Price

Mathematics ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1362
Author(s):  
Leopoldo Eduardo Cárdenas-Barrón ◽  
María José Lea Plaza-Makowsky ◽  
María Alejandra Sevilla-Roca ◽  
José María Núñez-Baumert ◽  
Buddhadev Mandal
Keyword(s):  
Optimal Solution ◽  
Inventory Model ◽  
Inventory System ◽  
Inventory Level ◽  
Selling Price ◽  
Lot Size ◽  
Inventory Models ◽  
Holding Costs ◽  
Imperfect Items ◽  
The Moment

Traditionally, the inventory models available in the literature assume that all articles in the purchased lot are perfect and the demand is constant. However, there are many causes that provoke the presence of defective goods and the demand is dependent on some factors. In this direction, this paper develops an economic order quantity (EOQ) inventory model for imperfect and perfect quality items, taking into account that the imperfect ones are sent as a single lot to a repair shop for reworking. After reparation, the items return to the inventory system and are inspected again. Depending on the moment at which the reworked lot arrives to the inventory system, two scenarios can occur: Case 1: The reworked lot enters when there still exists inventory; and Case 2: The reworked lot comes into when the inventory level is zero. Furthermore, it is considered that the holding costs of perfect and imperfect items are distinct. The demand of the products is nonlinear and dependent on price, which follows a polynomial function. The main goal is to optimize jointly the lot size and the selling price such that the expected total profit per unit of time is maximized. Some theoretic results are derived and algorithms are developed for determining the optimal solution for each modeled case. It is worth mentioning that the proposed inventory model is a general model due to the fact that this contains some published inventory models as particular cases. With the aim to illustrate the use of the proposed inventory model, some numerical examples are solved.

scholarly journals Two Identification Methods for Dual-Rate Sampled-Data Nonlinear Output-Error Systems

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Jing Chen ◽  
Ruifeng Ding
Keyword(s):  
Stochastic Gradient ◽  
The Other ◽  
Identification Algorithm ◽  
Sampled Data ◽  
Unknown Parameters ◽  
Auxiliary Model ◽  
Identification Methods ◽  
Numerical Example ◽  
Output Error ◽  
Polynomial Transformation

This paper presents two methods for dual-rate sampled-data nonlinear output-error systems. One method is the missing output estimation based stochastic gradient identification algorithm and the other method is the auxiliary model based stochastic gradient identification algorithm. Different from the polynomial transformation based identification methods, the two methods in this paper can estimate the unknown parameters directly. A numerical example is provided to confirm the effectiveness of the proposed methods.

scholarly journals Filtering and predicting the cost of hidden perished items in an inventory model

2002 ◽  
Vol 15 (3) ◽  
pp. 235-245
Author(s):  
Lakhdar Aggoun ◽  
Lakdere Benkherouf
Keyword(s):  
Joint Distribution ◽  
Inventory Model ◽  
The State ◽  
Inventory Level ◽  
Discrete State ◽  
History Of ◽  
Accumulated Losses ◽  
The Cost ◽  
State Of The Environment ◽  
Recursive Estimators

This paper is concerned with a discrete time, discrete state inventory model for items of changing quality. Items are assumed to be in one of a finite number, M, of quality classes that are ordered in such a way that Class 1 contains the best quality and the last class contains the pre-perishable quality. The changes of items' quality are dependent on the state of the ambient environment. Furthermore, at each epoch time, items of different classes may be sold or moved to a lower quality class or stay in the same class. These items are priced according to their quality, and costs are incurred as items lose quality. Based on observing the history of the inventory level and prices, we propose recursive estimators as well as predictors for the joint distribution of the accumulated losses and the state of the environment.

scholarly journals Design and Fabrication of Small Vertical-Take-Off-Landing Unmanned Aerial Vehicle

2018 ◽  
Vol 152 ◽  
pp. 02023 ◽  
Author(s):  
Yasir Ashraf Abd Rahman ◽  
Mohammad Taghi Hajibeigy ◽  
Abdulkareem Shafiq Mahdi Al-Obaidi ◽  
Kean How Cheah
Keyword(s):  
Design Methodology ◽  
The Other ◽  
Long Distance ◽  
Open Spaces ◽  
Flight Tests ◽  
Flight Range ◽  
Horizontal Flight ◽  
Vtol Uav ◽  
Aerial Vehicle ◽  
Horizontal Thrust

Modern UAVs available in the market have well-developed to cater to the countless field of application. UAVs have their own limitations in terms of flight range and manoeuvrability. The traditional fixed-wing UAVs can fly for long distance but require runways or wide-open spaces for take-off and landing. On the other hand, the more trending multirotor UAVs are extremely manoeuvrable but cannot be used for long-distance flights because of their slower speeds and relatively higher consumption of energy. This study proposed the implementation of hybrid VTOL UAV which has the manoeuvring advantage of a multirotor UAV while having the ability to travel fast to reach a further distance. The design methodology and fabrication method are discussed extensively which would be followed by a number of flight tests to prove the concept. The proposed UAV would be equipped with quadcopter motors and a horizontal thrust motor for vertical and horizontal flight modes respectively.

Making Music, Building Roads

2021 ◽  
pp. 62-72
Author(s):  
Penny Harvey
Keyword(s):  
The Other ◽  
British Broadcasting Corporation ◽  
Long Distance ◽  
Music Making ◽  
Growing Body ◽  
Engineered Systems ◽  
The One ◽  
Relational Capacities ◽  
The Relationship ◽  
Sixtieth Anniversary

This chapter explores how the analyses of audible infrastructures presented in this volume connect to the established and growing body of literature on civic infrastructures from scholars in the humanities and social sciences. There are clearly convergent interests between those who work on roads, water, and energy systems, on the one hand, and those who study the production, circulation, and reproduction of sound, on the other. To analyze the materialities of music making, as with civic infrastructures, is to investigate the relational capacities of the materials from which things are made, the diverse types of labor through which these materials become integral to their emergent forms, and the uneven distribution of access to the wider structures that underpin the circulation and reproduction of such forms. In particular, the chapter focuses on how the relationship between the hardware of engineered systems and the software of sociality creates new possibilities for thinking about the politics of infrastructure. The chapter explores these resonances between audible and civic infrastructures by considering the M1 Symphony, a work commissioned by the British Broadcasting Corporation to mark the sixtieth anniversary of the opening of Britain’s first long-distance motorway. The example provokes reflection on the relationship between media and infrastructure, between composition and improvisation, and between ontological experiment and artful design.

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