scholarly journals A System to Determine the Optimal Work-in-Progress Inventory Stored in Interoperation Manufacturing Buffers

2019 ◽  
Vol 11 (14) ◽  
pp. 3949 ◽  
Author(s):  
Grznár ◽  
Gregor ◽  
Mozol ◽  
Krajčovič ◽  
Dulina ◽  
...  
Keyword(s):  
Lead Time ◽  
Inventory Cost ◽  
Work In Progress ◽  
Optimal Capacity ◽  
Wip Inventory ◽  
Automotive Production ◽  
The Individual ◽  
The Cost ◽  
Production Company

Continuous cost reduction is a subject of interest for almost every production company. The cost reflects the competitiveness and sustainability of the business. Many company costs are linked to the effectiveness of production. One such cost is the work-in-progress (WIP) inventory cost. The present article deals with the design of a system for calculating the optimal WIP inventory stored in a manufacturing buffer, which, in the long term, provides the lowest costs. The main goal of the article is to design a new system that allows for the calculation of the optimal capacity of interoperation manufacturing buffers and thus the calculation of the optimal WIP inventory, which influences the lead time and cost. The newly designed system consists of algorithms that describe various steps, many of which use mathematical models. The individual blocks of algorithms are described, and the proposed system is verified and validated by simulation of the production line in the automotive production company.

Considerations on the optimal processing capacity of beet sugar factories

2020 ◽  
pp. 363-379
Author(s):  
Rudolf Schick
Keyword(s):  
Sugar Industry ◽  
Cane Sugar ◽  
Production Costs ◽  
Processing Capacity ◽  
Transport Costs ◽  
Optimal Capacity ◽  
Optimal Processing ◽  
Beet Sugar ◽  
The Individual ◽  
The Cost

The economic situation of the European sugar industry is currently very tense. The expected introduction of a climate-neutral mode of operation by 2050 will require considerable investment in the coming decades. This will further strengthen the cost advantages of the cane sugar industry, which, in contrast to the beet sugar industry, has for many years been obtaining most of its energy requirements from the renewable fuel bagasse. In order to remain competitive with the cane sugar industry, further reductions in production costs are necessary. As it is hardly possible to increase efficiency through technological improvements, the most promising measures to reduce production costs will be to further increase the processing capacity of the individual factories and possibly extend the campaign. Using a simplified mathematical model, the influence of transport costs, labour costs and constant costs on the optimal capacity of beet sugar factories is investigated. The lowest production costs for white sugar are used as an optimality criterion.

scholarly journals Pengembangan Model Vendor Managed Inventory dengan Banyak Retailer yang Mempertimbangkan Ketidakpastian Lead Times

2018 ◽  
Vol 7 (1) ◽  
pp. 41
Author(s):  
Carles Sitompul ◽  
Paulina Ariningsih ◽  
Ida Bagus Deva Narswara Santosa
Keyword(s):  
Inventory Management ◽  
Lead Time ◽  
Mathematical Formulation ◽  
Lead Times ◽  
Approximation Model ◽  
Vendor Managed Inventory ◽  
Inventory Cost ◽  
Inventory Management System ◽  
Total Inventory ◽  
The Cost

<p><em>An inventory management system in supply chains called Vendor Managed Inventory (VMI) is very promising due to the cost efficiency resulted from implementing such system. This research aims to develop a vendor managed inventory for multiple retailers. The model also takes into account lead time uncertainties from vendor to its retailers. A mathematical formulation for VMI with multiple retailers is first developed using deterministic lead times.  Subsequently, lead times uncertainties are then taken into account where modes lead times are broken into two components: modes and delays, each with their respective probabilities. In turn, an approximation model is used to solve the problem because the complexity aroused from the model is difficult to solve using analytical methods. It is shown that the proposed approximation method is able to solve VMI problem with multiple retailers and uncertain lead times.  Furthermore, the total inventory cost is significantly reduced when compared to the usual economic order quantity method because stockouts are less frequent. </em></p>

scholarly journals Long-term memory of individual identity in ant queens

2007 ◽  
Vol 3 (5) ◽  
pp. 459-462 ◽  
Author(s):  
Stephanie Dreier ◽  
Jelle S van Zweden ◽  
Patrizia D'Ettorre
Keyword(s):  
Social Life ◽  
Individual Recognition ◽  
Evolution Of Cooperation ◽  
Long Term Memory ◽  
Individual Identity ◽  
Term Memory ◽  
The Individual ◽  
The Cost ◽  
First Time

Remembering individual identities is part of our own everyday social life. Surprisingly, this ability has recently been shown in two social insects. While paper wasps recognize each other individually through their facial markings, the ant, Pachycondyla villosa , uses chemical cues. In both species, individual recognition is adaptive since it facilitates the maintenance of stable dominance hierarchies among individuals, and thus reduces the cost of conflict within these small societies. Here, we investigated individual recognition in Pachycondyla ants by quantifying the level of aggression between pairs of familiar or unfamiliar queens over time. We show that unrelated founding queens of P. villosa and Pachycondyla inversa store information on the individual identity of other queens and can retrieve it from memory after 24 h of separation. Thus, we have documented for the first time that long-term memory of individual identity is present and functional in ants. This novel finding represents an advance in our understanding of the mechanism determining the evolution of cooperation among unrelated individuals.

scholarly journals ANALISA KAPASITAS OPTIMAL LAPANGAN PENUMPUKAN DI PANGKALAN LONTANGNGE PELABUHAN PAREPARE

2019 ◽  
Vol 22 (1) ◽  
pp. 76-80
Author(s):  
Anugrah Amaliah
Keyword(s):  
Queuing Theory ◽  
Waiting Times ◽  
Short Term ◽  
Optimal Capacity ◽  
Port Planning ◽  
Optimum Cost ◽  
The One ◽  
The Cost ◽  
Capacity Loading

Abstrak Perencanaan pelabuhan yang tidak tepat dapat mengakibatkan pelayanan pelabuhan yang kurang efisien. Optimasi digunakan untuk menemukan sebuah kondisi yang diperlukan untuk mencapai hasil terbaik dari situasi yang ada. Hal ini dicapai dengan menyeimbangkan antara biaya pelayanan yang ada dengan biaya tunggu yang diakibatkan oleh pelayanan yang ada. Biaya pelayanan tergabung dalam pengoperasian fasilitas sedang biaya tunggu menyatakan biaya menunggu bagi pelanggan. Menambah ataupun meningkatkan pelayanan berarti dapat mengurangi waktu tunggu pelanggan. Penelitian ini bertujuan untuk menganalisis kapasitas optimal Lapangan Penumpukan  Petikemas Lontangnge Pelabuhan Parepare untuk jangka pendek, jangka menengah dan jangka panjang, serta menentukan dimensi ukuran dari Lapangan Penumpukan Petikemas Lontangnge Pelabuhan Parepare. Analisa dilakukan dengan menggunakan teori antrian, dimana teori ini membantu dalam menghitung biaya-biaya akibat pelayanan yang menunggu. Perhitungan ini dilakukan dengan menganalisa data muatan bongkar-muat (B/M) petikemas dan data barang pada petikemas untuk memperoleh biaya yang ada. Selain itu, dilakukan pula perhitungan daya dukung tanah untuk menentukan tinggi tumpukan petikemas dan kapasitas lapangan. Pada hasil penelitian ini, diperoleh untuk Jangka Pendek biaya optimum untuk Lapangan Penumpukan  Petikemas Lontangnge Pelabuhan Parepare adalah Rp. 27,479,774,886.03 dengan luas dimensi lapangan adalah 4700 m2. Sedangkan untuk Jangka Menengah dan Jangka Panjang adalah Rp. 36,690,983,344.01 dengan luas dimensi lapangan adalah 25000 m2.  Kata Kunci: Optimasi, Kapasitas Lapangan, Muatan B/M.   Abstract Improper port planning results in less efficient port services. Optimization is used to find the one condition to find the best outcome of the situation. This is achieved by balancing the cost of existing services with the waiting costs caused by existing services. Service charges are incorporated in the operation of the facility while the waiting costs state the waiting costs for customers. Adding or improving services means reducing customer waiting times. The aim of this research is to analyze the optimal capacity of Lontangnge Container Yard Port of Parepare, medium and long term, and to determine the dimension of container yard’s size. The analysis is done by using queuing theory, where the costs of waiting service can be calculated. This calculation is done by analyzing data of loading-discharging payload and goods data on container to obtain cost. In addition, the calculation of soil bearing capacity is also determined the height of container pile and Container Yard (CY) capacity. In the results of this study, obtained for the short-term optimum cost for the Lontangnge Parcel Container Parepare Field is Rp. 27,479,774,886.03 with the width of field dimension is 4700 m2. While for the Medium Term and Long Term is Rp. 36,690,983,344,01 with the field dimension is 25000 m2.  Keywords : Optimation, CY Capacity, Loading-Discharging Goods.    

Modeling Simulation and Optimization Study of Fresh Seafood Inventory Ordering Policies Based on Witness

2012 ◽  
Vol 461 ◽  
pp. 541-546
Author(s):  
Zhao Hua Tan ◽  
Ya Hui Zhang
Keyword(s):  
Lead Time ◽  
Inventory Cost ◽  
Simulation And Optimization ◽  
Price Discounts ◽  
Optimization Study ◽  
Total Inventory ◽  
Ordering Policies ◽  
Time Price ◽  
The Cost ◽  
Variation Trends

It is possible to reduce the inventory cost by choosing the proper ordering policies. Considering the distinctive nature of perishable products, it is much more important to control the inventory levels properly. In this paper, we select the fresh seafood as the object of our study and build a simulation model based on Witness to analyse the inventory cost. In the model, we consider constraint conditions such as replenishment lead time, price discounts and so on. We also analyse the variation trends of total inventory cost together with the changes of parameters in three models with different ordering policies and obtain the parameters of the optimum policy by comparing the cost in that three models.

The Cost of War

2020 ◽  
Author(s):  
Stephen Garton
Keyword(s):  
Long Term Effects ◽  
Post Traumatic Stress ◽  
Cost Of War ◽  
Post Traumatic ◽  
Nuanced Understanding ◽  
New Perspective ◽  
The Individual ◽  
The Cost ◽  
Effects Of War

War has shaped Australian society profoundly. When we commemorate the sacrifices of the Anzacs, we rightly celebrate their bravery, but we do not always acknowledge the complex aftermath of combat. In The Cost of War, Stephen Garton traces the experiences of Australia’s veterans, and asks what we can learn from their stories. He considers the long-term effects of war on returned servicemen and women, on their families and communities, and on Australian public life. He describes attempts to respond to the physical and psychological wounds of combat, from the first victims of shellshock during WWI to more recent understandings of post-traumatic stress disorder. And he examines the political and social repercussions of war, including debates over how we should commemorate conflict and how society should respond to the needs of veterans. When the first edition of The Cost of War appeared in 1996, it offered a ground-breaking new perspective on the Anzac experience. In this new edition, Garton again makes a compelling case for a more nuanced understanding of the individual and collective costs of war.

ELASTOMERS IN THE OIL FIELD

2013 ◽  
Vol 86 (3) ◽  
pp. 449-469 ◽  
Author(s):  
Rustom Mody ◽  
David Gerrard ◽  
Jim Goodson
Keyword(s):  
Petroleum Reservoirs ◽  
Oil Field ◽  
Well Performance ◽  
Oil Boom ◽  
Well Completion ◽  
Reliable Performance ◽  
The Individual ◽  
Almost All ◽  
The Cost

ABSTRACT Even before Spindletop “gushered” in the great Texas oil boom in 1901, rubber chemistry and technology played a key role in the pressure and flow control of hydrocarbons from petroleum reservoirs. This key role for rubber in the oil field continues today, where the cost of construction of an oil or gas well can exceed a billion dollars. Almost all equipment used in downhole drilling and completion operations currently depends on elastomers and other sealing materials to provide steady, reliable performance during service. Although the cost of the individual seals used downhole in a well represents only a fraction of the total well cost, the seals are critical to well performance and safety. Sealing mechanisms are at the heart of any drilling, completion, or production system and are the primary components on which the functional success and longevity of the system rests. Modern drilling systems, with their significant use of onboard electronic components and sensors, rely heavily on nonmetallic seals to prevent well environmental contamination while withstanding sustained dynamic loadings throughout service. Well completion systems can be categorized by either relatively short-term applications, after which seals can be changed or maintained, or long-term applications, in which seals are expected to perform without change or maintenance for 20 years or longer. The assurance of these systems' continued performance throughout the life of the well, whether the expected life is short or long, is of vital importance.

Optimization model for transportation planning with demand uncertainties

2014 ◽  
Vol 114 (8) ◽  
pp. 1229-1245 ◽  
Author(s):  
Dilupa Nakandala ◽  
Henry Lau ◽  
Jingjing Zhang
Keyword(s):  
Lead Time ◽  
Numerical Study ◽  
Cost Optimization ◽  
Inventory System ◽  
Cost Functions ◽  
Inventory Cost ◽  
Content Type ◽  
Study Results ◽  
The Cost ◽  
Cost Components

Purpose – The purpose of this paper is to investigate the total cost function of an inventory system with a reorder point/order quantity policy where the lead time is controllable based on the cost paid by the buyer for the service. Design/methodology/approach – Cost functions are presented to investigate how the changes in lead time affect different components of inventory cost in the present of random demand. Two methods including an iteration technique and Simulated Annealing (SA) algorithm are presented to deal with the cost optimization issue. The application of proposed model is illustrated using numerical case scenarios. Findings – The cost functions show that besides ordering cost, change in stochastic demand during lead time is the major factor that affects the other cost components such as holding and penalty costs. This finding is validated by numerical study. Results also show that performance of SA algorithm is highly similar to iteration methodology, while the former one is easier in application. Practical implications – This paper develops less complex, more pragmatic methods, easily adoptable by logistics managers for cost minimization. This paper also analyzes and highlights the unique characteristics and features of these two approaches that can help practitioners in making the right choice when faced with the identified logistics issue. Originality/value – This research explicitly investigate impacts of changing lead time on inventory cost components which enables informed decision making and inventory system planning for cost optimization by logistics practitioners. Two methodologies that can be easily used by practitioners without deep mathematical analysis and is cost effective are introduced to solve the optimization problem. Detailed roadmaps of how to implement proposed approaches have been illustrated by different case scenarios.

Primary varicose veins

Phlebologie ◽  
2010 ◽  
Vol 39 (03) ◽  
pp. 133-137
Author(s):  
H. Partsch
Keyword(s):  
Varicose Veins ◽  
Compression Therapy ◽  
Daily Practice ◽  
Clinical Severity ◽  
Compression Stockings ◽  
Primary Varicose Veins ◽  
The Cost ◽  
Convincing Data ◽  
Long Term Studies

SummaryBackground: Compression stockings are widely used in patients with varicose veins. Methods: Based on published literature three main points are discussed: 1. the rationale of compression therapy in primary varicose veins, 2. the prescription of compression stockings in daily practice, 3. studies required in the future. Results: The main objective of prescribing compression stockings for patients with varicose veins is to improve subjective leg complaints and to prevent swelling after sitting and standing. No convincing data are available concerning prevention of progression or of complications. In daily practice varicose veins are the most common indication to prescribe compression stockings. The compliance depends on the severity of the disorder and is rather poor in less severe stages. Long-term studies are needed to proof the cost-effectiveness of compression stockings concerning subjective symptoms and objective signs of varicose veins adjusted to their clinical severity. Conclusion: Compression stockings in primary varicose veins are able to improve leg complaints and to prevent swelling.

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