...Chapter 7 Inventory Models Inventory refers to idle goods or materials that are held by an organization for use sometime in the future. Items carried in inventory include raw materials, purchased parts, components, subassemblies, work-in-process, finished goods, and supplies. One reason organizations maintain inventory is that it is rarely possible to predict sales levels, production times, demand, and usage needs exactly. Thus, inventory serves as a buffer against uncertain and fluctuating usage and keeps a supply of items available in case the items are needed by the organization or its customers. While inventory serves an important and essential role, the expense associated with financing and maintaining inventories is a substantial part of the cost of doing business. In large organizations, the cost associated with inventory can run into the millions of dollars. Two important questions that must be answered in order to effectively manage inventories are as follows: 1. How much should be ordered when the inventory for an item is replenished? 2. When should the inventory be replenished? The purpose of this chapter is to show how quantitative models can assist in making these decisions. We will first consider deterministic inventory models in which we assume that the rate of demand for the item is constant or nearly constant. Later we will consider probabilistic inventory models in which the demand for the item fluctuates and can be described only in probabilistic...
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...Inventory Control Models Quantitative Analysis Inventory is often discussed in such a manner that it seems unimportant, but this couldn’t be any further from the truth. The manner in which an organization controls its inventory can decide its fate. Is it too hard to imagine a store advertising a large three day sale but did not forecast correctly and was exhausted of the sale items within hours of the start of the sale. Customers may feel duped into traveling to the store under false pretenses. Or, imagine huge quantities of Christmas items left in the warehouse days after Christmas. The loss of profits or requirement to sell off the items to make room on the shelves could devastate a small business. Inventory is defined as any stored resource that is used to satisfy a current or future need (Render, 2012). Running a successful retail or wholesale business is all about allocating funds wisely. Organizations need to buy only what is necessary of any one item in order to keep sales going, and prevent stock-outs. The rest of the funds can be used to increase product range, increase marketing or pay debts. Items that sit on the shelf gathering dust for months are no use to anyone - an accurately kept inventory system allows managers to quickly identify slow moving products, put them on special offer and release the cash for higher turnover goods. Some companies rely on raw materials to produce products. A lack of inventory can cause the company to miss expended production...
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...forecasting model and recommending an inventory control model by ordering optimum units to help them solve their current issue. As a result, an Economic Order Quantity (EOQ) and a variable cost was recommended to help them reduce their product stock outs. The shortage of raw material for production always makes the process discontinuous and reduces the productivity. The ABC analysis technique for the inventory control system is first used to identify the most important multiple products and then the economic order quantity (EOQ) of each product is...
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...A Multi-Product Capacitated Inventory-Location Model with Risk Pooling ¹Noura A. Al Dhaheri, ²Ali Diabat ¹Department of Engineering Systems and Management, Masdar Institute, UAE 2 MASDAR Institute of Science and Technology, United Arab Emirates naldhaheri@masdar.ac.ae; adiabat@masdar.ac.ae Abstract - In this paper, a novel formulation for the capacitated warehouse inventory-location model with risk pooling for multiple products is proposed. A single plant ships different types of products to retailers via a network of warehouses. The locations and inventory policies of the warehouses are chosen so as to minimize the sum of fixed facility location, transportation, and inventory carrying costs. The warehouses retain safety stock so as to maintain appropriate service levels in the face of uncertain demand at the retailers for multiple products. Keywords - integer programming, location-inventory, multiple products, supply chain optimization I. INTRODUCTION Supply Chain Management spans all movement and storage of raw materials, work-in-process inventory, and finished goods from point of origin to point of consumption [1]. It involves decisions on facility location, technology selection, inventory management, and distribution. These decisions can be categorized into three different levels: strategic, tactical, and operational. Particularly in today’s competitive business environment, the importance of integrating these decisions so as to minimize costs and maximize customer satisfaction...
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...Business Inventory Control Meghan Farrar, Amanda May, Nancy Dinges, Scott Moore and Bianca Holmes American Public University Introduction “Inventory is one of the most expensive and important assets to many companies, representing as much as 50% of total invested capital. Managers have long recognized that good inventory control is crucial” (Render et al, 2011). Therefore, it is really no surprise that companies place such a high importance on inventory control. An analysis of the planning and forecasting process, as well as the uses of inventory control will certainly verify the significance of inventory control in the business environment. In addition, by utilizing several inventory methods: economic order quantity, production run and quantity discount models, in hypothetical inventory scenarios for McDonald’s, there will be sufficient evidence to support the accuracy and importance of inventory control. Inventory Control: Planning & Forecasting The importance of inventory control and planning cannot be overstated no matter what the size of the business. Inventory control is a process managers must master in order to most effectively and efficiently deliver their company’s products or services to the customer (Render et al, 2011). The two most essential steps in effectively managing inventory are planning and forecasting. Inventory planning encompasses the “what” in terms of specific inventory stock requirements and addresses how the inventory will be...
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...transshipment models to inventory applications? Why or why not? Is the transportation model an example of decision making under certainty or decision making under uncertainty? Why? Can we apply transshipment models to inventory applications? Why or why not? Yes, transshipment models can be applied to inventory applications. This will ensure lower costs through proper management and disbursement of the inventory while providing faster response times. The inventory levels can be managed by location in order to ensure minimal levels and the shipping will occur for less cost and faster service due to inventory placement within regions (Taylor III, 2011). Is the transportation model an example of decision making under certainty or decision making under uncertainty? Why? The transportation model is an example of decision making under certainty. The data, in this case the route and items, has to be known in order for the decision making to be determined under certainty (Taylor III, 2011). Explain the assignment model and how it facilitates in solving transportation problems. What benefits would be gained from using this model? 2ND RESPONSE Can we apply transshipment models to inventory applications? Why or why not? Yes, it does seem that transshipment models can be applied to inventory applications. Inventory applications deal with transporting goods to different destinations just like the transshipment models. By applying a transshipment model to inventory applications,...
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...Production Systems Assumptions: * available set of machine technology is fixed (short term production control decisions) * organization of production has been determined Production system * collection of material, labour, capital, and knowledge that goes into manufacture of a product * how the collection of components is put together in a specific situation defines a particular system Taxonomy of Production Systems * by different criteria and meaningful analysis applied * by production flow characteristics Production processes can be either continuous or discrete (or one at a time fashion). Three Major Building Blocks in a Production System 1. Machine Technology Base (or the Tools for Production) * Sets boundaries on the processes that can be employed in converting inputs to finished products * Long term planning decisions * Major component of productivity improvement 2. Organization * Product layout * Organizes people and machines that is satisfactory for the production of a single product * Sequential operations * Flow line organization of a production * Process layout * According to the manufacturing process involved in the production of products * Machinery is grouped based on common purposes * When there are a large number of different products using the same machinery but not necessarily in the same order * Job shop ...
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...TRUE/FALSE 1. According to the global company profile, Amazon.com's advantage in inventory management comes from its almost fanatical use of economic order quantity and safety stock calculations. False (Global company profile, easy) 2. A major challenge in inventory management is to maintain a balance between inventory investment and customer service. True (Introduction, easy) 3. Which item to order and with which supplier the order should be placed are the two fundamental issues in inventory management. False (Introduction, moderate) 4. One function of inventory is to take advantage of quantity discounts. True (Functions of inventory, easy) 5. Work-in-process inventory is devoted to maintenance, repair, and operations. False (Functions of inventory, easy) 6. ABC analysis classifies inventoried items into three groups, usually based on annual units or quantities used. False (Inventory management, easy) 7. In ABC analysis, "A" Items are the most tightly controlled. True (Inventory management, moderate) 8. ABC analysis is based on the presumption that carefully controlling all items is necessary to produce important inventory savings. False (Inventory management, easy) 9. Cycle counting is an inventory control technique exclusively used for cyclical items. False (Inventory management, moderate) 10. One advantage of cycle counting is that it maintains accurate inventory records. True (Inventory management, moderate) 11. In cycle counting, the frequency of item counting...
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...(Heizer/Render) Chapter 12 Inventory Management 1) According to the global company profile, Amazon.com's advantage in inventory management comes from its almost fanatical use of economic order quantity and safety stock calculations. Answer: FALSE Diff: 1 Topic: Global company profile Objective: no LO 2) A major challenge in inventory management is to maintain a balance between inventory investment and customer service. Answer: TRUE Diff: 1 Topic: The importance of inventory Objective: no LO 3) Which item to order and with which supplier the order should be placed are the two fundamental issues in inventory management. Answer: FALSE Diff: 2 Topic: The importance of inventory Objective: no LO 4) One function of inventory is to take advantage of quantity discounts. Answer: TRUE Diff: 1 Topic: Functions of inventory Objective: no LO 5) Work-in-process inventory is devoted to maintenance, repair, and operations. Answer: FALSE Diff: 1 Topic: Functions of inventory Objective: no LO 6) ABC analysis classifies inventoried items into three groups, usually based on annual units or quantities used. Answer: FALSE Diff: 1 Topic: Managing inventory Objective: LO12-1 7) In ABC analysis, "A" Items are the most tightly controlled. Answer: TRUE Diff: 2 Topic: Managing inventory Objective: LO12-1 1 Copyright © 2011 Pearson Education, Inc 8) ABC analysis is based on the presumption that carefully controlling all items is necessary to produce important inventory savings. Answer:...
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...consisting of following members: Name | ID No. | Nakib H. Khan | :17-030 | Rokshana Akter | :17-018 | Taslima Parvin | :19-059 | Rezaul Hasan Bhuiyan | :19-075 | Md Anisur Rahman | :20-021 | Md Shahriar Shaon | :21-071 | Date of Submission and Presentation: August 30, 2015 Letter of Transmittal August 30, 2015 Dr. K. M. Salah Uddin Associate Professor Department of Management Information Systems University of Dhaka MBA (Evening) Program Subject: Term Paper on Simulation of Inventory System. Dear Sir, As this term paper is an inseparable part of our Simulation and System Modeling course, we were asked to prepare a term paper on “Simulation of Inventory System”. We devoted our skills and knowledge to efficiently and effectively handle this task. While preparing the term paper, we utilized what we have learnt throughout the semester in this course and capitalized on this opportunity to acquire some in-depth knowledge regarding “Simulation of Inventory System”. We are pleased to we submit hereby the term paper for your kind evaluation. We are always available if it is necessary for any query. Sincerely yours, Md Anisur Rahman ID # 20- 021 In favor of the group Acknowledgement First of all we would like to express our gratitude to omnipotent and almighty Allah, whose invisible guidance helped us to complete this term paper. Then we would like to thank our honorable teacher for assigning us such an interesting topic which is an indispensable...
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...Teknologi Full paper Improving the Inventory Levels of a Blood Supply Chain Through System Dynamic Simulation Jafar Afshar*, Narjes Sadeghiamirshahidi, Ali Reza Firouzi, Seyed Mojib Zahraee, Syed Ahmad Helmi Syed Hassan Faculty of Mechanical Engineering, Department of Industrial Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia *Corresponding author: amir_1065@yahoo.com Article history Abstract Received :1 January 2014 Received in revised form : 15 February 2014 Accepted :18 March 2014 The blood supply chain is a complex system with a multi-echelon structure. Hence, the integration of various interconnected elements, which should be synchronized appropriately, is a necessity to meet the patients’ requirements. The performance of the blood supply chain is a function of different variables that are dependent of each other. Therefore, the main aim of the chain is the optimization of the overall supply chain by considering the dynamic behavior of the system. The purpose of this study is to develop a system dynamic simulation model for a complex blood supply chain in order to improve the average level of inventories. The developed model is based on three echelons with a centrality on a regional blood center. The performance of the supply chain network in the current condition is investigated and based on the objectives, 17 scenarios were experimented for improving the average level of inventories to avoid outdates while there are...
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...Explanation on the basis on which inventory management is done, the different type of inventory models in the context of the assignment given. The process in which each of them is used. This would help you decide the right inventory model. Pl go through this properly. As a growing corporation in the e-commerce retail apparel industry, XYZ has recently been under pressure to package and ship a higher volume of clothes. In order for the corporation to meet this demand, XYZ’s executive staff must decide either to increase its staffs’ hours in the logistics department and potentially hire another employee or bulk ship inventory to Amazon warehouses to be fulfilled through Amazon Prime. The executive team was able to recreate these two scenarios through linear programing and has determined that the company will seek more profit by utilizing Amazon’s fulfillment services. After analyzing the sales model of using Amazon Inc. fulfillment the recommendations for management are to focus on inventory limits and create patterns that will help forecast the inventory needed. By seeking out inventory models, which resolves dual problems of maintaining sufficient inventories to meet demand, we are able to successfully determine the appropriate inventory limits needed for this operation. Now we see that there could have been many solutions like for low values of demand, fulfillment should be done in-house and for high values direct shipping should be used. When demand is comparable to capacity...
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...the data provided for Roma and Cantazaro, following is the numerical analysis of regional warehousing model and transit point experiment model. Short haul transportation cost will remain unchanged as the trucks will still be delivering to retailers. Case 1: Roma Average Inventory Demand filled by regional warehouse Order cycle Current Model (values in Lire on per piece basis) Operating cost per order cycle Inventory cost per order cycle Transportation cost (10 trucks in 8 days delivering 1200 items) Total cost per piece per order cycle 1200 154.8 7.751937984 (1200/154.8) 961.3333333 (3605*(8/30)) 276 (1035*(8/30) 3166.666667 (0.38m*10/1200) 4404 8 Days TPE Model (values in Lire on per piece basis) Operating cost (8days) Inventory cost Transportation cost (1 small and one big truck daily for 8days) 192.2666667 (20% of 3605)*(8/30) 0 No inventory 3866.666667 (8*(0.38+0.2)m/1200 4058.933333 345.0666667 Saving (Lire per piece per 8 days) Case 2: Catanzaro Average daily demand filled by regional warehouse Demand filled by regional warehouse Order cycle Current Model (values in Lire on per piece basis) Operating cost per order cycle Inventory cost per order cycle Transportation cost (5 large and 4 small trucks in 8 days delivering 1200 items) Total cost per piece per order cycle Transit Point Experiment Scenario 1 (2 small trucks daily) Operating cost per cycle Inventory cost Transportation cost ( 2 small truck daily partially loaded) 58.68 780 13.29243354 (780/58.68) 1551...
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...This article was downloaded by: [123.255.73.85] On: 02 November 2013, At: 21:59 Publisher: Institute for Operations Research and the Management Sciences (INFORMS) INFORMS is located in Maryland, USA Operations Research Publication details, including instructions for authors and subscription information: http://pubsonline.informs.org Inventory Management of a Fast-Fashion Retail Network Felipe Caro, Jérémie Gallien, To cite this article: Felipe Caro, Jérémie Gallien, (2010) Inventory Management of a Fast-Fashion Retail Network. Operations Research 58(2):257-273. http://dx.doi.org/10.1287/opre.1090.0698 Full terms and conditions of use: http://pubsonline.informs.org/page/terms-and-conditions This article may be used only for the purposes of research, teaching, and/or private study. Commercial use or systematic downloading (by robots or other automatic processes) is prohibited without explicit Publisher approval. For more information, contact permissions@informs.org. The Publisher does not warrant or guarantee the article’s accuracy, completeness, merchantability, fitness for a particular purpose, or non-infringement. Descriptions of, or references to, products or publications, or inclusion of an advertisement in this article, neither constitutes nor implies a guarantee, endorsement, or support of claims made of that product, publication, or service. Copyright © 2010, INFORMS Please scroll down for article—it is on subsequent pages INFORMS is the largest professional...
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...11-1 Inventory Management 11-2 Inventory Management CHAPTER Operations Management 11 William J. Stevenson Inventory Management 8th edition McGraw-Hill/Irwin Operations Management, Eighth Edition, by William J. Stevenson Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved. 11-3 Inventory Management 11-4 Inventory Management Types of Inventories Inventory: a stock or store of goods Independent Demand A Dependent Demand Raw materials & purchased parts • Partially completed goods called work in progress • • Finished-goods inventories • B(4) C(2) D(2) E(1) D(3) F(2) (manufacturing firms) or merchandise (retail stores) Independent demand is uncertain. Dependent demand is certain. 11-5 Inventory Management Types of Inventories (Cont’d) (Cont’ 11-6 Inventory Management Functions of Inventory • • Replacement parts, tools, & supplies Goods-in-transit to warehouses or customers • • • • To meet anticipated demand To smooth production requirements To decouple operations To protect against stock-outs 11-7 Inventory Management Functions of Inventory (Cont’d) (Cont’ To take advantage of order cycles To help hedge against price increases To permit operations To take advantage of quantity discounts 11-8 Inventory Management Objective of Inventory Control • • • • • To achieve satisfactory levels of customer service while keeping inventory...
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