The traditional (Q,r) inventory control model assumes that the date at which the order is entered is the same as the date at which it is requested or expected to be delivered. Hence, the penalty cost is incurred when the customer places the order if inventory is unavailable. This is a reasonable assumption for retail systems and most distribution centers (DC), but not for an assemble-to-order (ATO) environment. In this scenario, there is a delivery time which is usually pre-negotiated and in addition to considering the manufacturing process time and in some cases the outbound transportation time, it also has some safety time built-in. This safety time is defined by the manufacturer and represents information related to when the penalty is incurred. The main objective of this research is to develop a modified (Q,r) policy that incorporates the safety time, and to evaluate this policy in terms of expected inventory cost and expected penalty cost / late orders. The problem is addressed following the heuristic approach discussed by Hadley and Whitin (1963). Two main models are developed based on the following assumptions: 1) early shipments are allowed by the customer, and 2) no early shipments are allowed. The behavior of both models is analyzed mathematically and by means of numerical examples. It is shown that from a manufacturer perspective, the first model is preferred over the traditional (Q,r) model. However, it poses a threat for the long term business relationship with the customer because the service level deteriorates, and for the implications that early shipments have on the customer inventory. The behavior of the second model is strictly related to the problem being addressed. Its merits with respect to the traditional and the "early shipment" model are discussed. This discussion is centered on the coefficient of variation of the lead-time demand, the ratio (IC/pi), and the location of the supplier. A final model which is a hybrid of the previous two shipping policies is developed. The models developed in the course of this research are generalizations of the traditional (Q,r) model.

The telecommunications industry has been in the process of merging. However, the decline of Average Revenue Per User (ARPU) shows the saturation of mobile phone market. At the same time, the Directorate General of Telecommunications (DGT) has announced the implementation of number portability will be in January 2005. Therefore, the resort to sell handsets in high discounts is unavoidable to retain the existing customers and get the new subscribers. Because the high cost, short product lifecycle, diversity of usage, uncertainty of leading time in procurement and indefinite of consumers¡¦ demands, the management of handset inventory has been perplexed the telecommunication industry. This research tries to create an inventory model to provide the mobile phone companies a direction for deciding what the right order quantity is and when the re-order point is. It also can improve the satisfaction of customers and enforce the partnership with vendors. The vendor managed inventory (VMI) which is different from traditional inventory management is taken into consideration, and the target is the high-end function handset. The model will employ the data of average demand in the past few months and the decline curve of market price as the base. The relation of handsets has been created by using the characteristics of classified product. The methodology of time series analysis is used for this research. The construct of this handset inventory model is from the viewpoint of telecommunication industry.

<p>Introduction:</p><p>The growth of small business is fast and their impact on the economy is becoming bigger. How to manage the inventory effectively and efficiently often is a challenge for these small businesses. The study took place at HEM-SOL FORSALJNINGS AB, a company involved in gym sports equipment wholesale. For HEM-SOL two inventory problems, stock-out and overstock occur frequently. The company wants to improve its efficiency and is con-sidering a change in the inventory management.</p><p>Purpose:</p><p>The purpose of this study is to investigate the reasons behind the inventory management inefficiency in HEM-SOL, and then the proposed managerial suggestions will be presented to deal with the issues.</p><p>Method:</p><p>The study is considered as qualitative single-case study. Data collection is mainly through the interviews with the top manager and other staff involved in inventory control opera-tions. Secondary data is retrieved from the information system to provide the annual pur-chasing and sales report about twenty items using a purposive sampling approach. Data analysis follows the theoretical framework.</p><p>Conclusion:</p><p>Small businesses have limited financial resources and bargaining power. Long-distance suppliers, big fluctuation of demand and lack of formalized inventory control system result in HEM-SOL bad performance on inventory management. The authors analyze the col-lected data and establish a formal inventory control system as the solution to improve the company’s inventory management.</p>

<p>Today many companies face problems with inventory management. The importance of adequate inventory management has become more evident, while organizations try to reduce their costs and increase their service level.</p><p>This master thesis was conducted at VSM Group AB in Huskvarna, which is a manufacturer that produces and delivers sewing machines to a worldwide market. VSM Group AB has problems with the management and the refilling of the work-in-process (WIP) inventories and also with lack of information about component balance and location in the production and material planning system.</p><p>Therefore, the purpose of the thesis was to improve the control of the WIP inventories and the information about the components in the production and material planning system. In order to achieve the purpose, interviews and observations were performed, theories in inventory management were reviewed and the production process was studied.</p><p>Afterwards solutions for improvements were proposed. To solve the management and refilling problem, a kanban ordering system was proposed, which would use kanban cards to order components from the storages to the WIP inventories. To develop the component information displayed in the production and material planning system, an additional feature was proposed to the system. So instead of showing one inventory balance for each component, the system would display balances for three different places in the factory: the goods arrival and quality control area, the storage and the production.</p><p>The proposed solutions can provide several benefits to the company. The kanban ordering system can increase the material handlers’ efficiency, set a standard refilling quantity and be a tool for reducing the WIP inventory levels. The more detailed information in the production and material planning system can improve the decision making for the purchasers and planners and give the ability to measure the flow and level of material inside the factory.</p><p>These solutions will provide a more appropriate inventory management to the company, with better control of the components and improved information quality.</p>

Sammanfattning Syfte - Syftet med denna studie är att bidra till ökad förståelse för hur lager kan styras när varierad efterfrågan förekommer. För att uppnå syftet är målet med studien att sammanställa processer som underlättar för lagerstyrning vid varierad efterfrågan. Detta möjliggörs genom att besvara följande frågeställningar: 1. Vilka metoder för säkerhetslagerberäkning och lagerstyrning är lämpliga när hänsyn bör tas till varierad efterfrågan? 2. Hur påverkas lagerförings- och ordersärkostnader av olika sätt att styra lager vid varierad efterfrågan? Metod - Teorier angående lagerstyrning vid varierad efterfrågan samlades in via litteraturstudier. En fallstudie genomfördes för att applicera det teoretiska ramverket på empiri från fallföretaget. Empiri samlades in via intervjuer och dokumentationsstudier och utgjorde en grund för beräkningar och vidare analys. Resultat - Lämplig säkerhetslagerberäkning vid varierad efterfrågan anses vara SERV2 som tar hänsyn till antalet bristtillfällen och ger ett bra mått på lagertillgängligheten över tid. De dynamiska lagerstyrningsmetoderna Silver &amp; Meal samt Wagner-Whitin kan i större utsträckning hantera stora variationer i efterfrågan gentemot beställningspunktssystem. Beräkningar resulterade i att Wagner-Whitin var den lagerstyrningsmetod som i majoriteten av fallen genererar lägst totalkostnad när hänsyn tas till lagerförings- och ordersärkostnader. En process för lagerstyrning vid varierad efterfrågan har kartlagts där indata i form av metod- och resursobjekt redogörs. Detta för att bidra till ökad förståelse för hur lager kan styras vid varierad efterfrågan. Implikationer - Inom denna studie framgår det att kostnaderna för lagerstyrningen vid varierad efterfrågan kan sänkas med hjälp av dynamiska lagerstyrningsmetoder. Det är dock viktigt med trovärdig indata för att generera tillförlitliga resultat. Begränsningar - Inom de dynamiska lagerstyrningsmetoderna vägs ordersärkostnad mot lagerföringskostnad och genererar det mest ekonomiska alternativet ur lagerstyrningens perspektiv. Det måste inte vara det bästa ur ett helhetsperspektiv då förändrade orderkvantiteter kan påverka andra delar av materialflödet. De processkartor som är upprättade utgår från den valda lösningen, detta begränsar tillämpningen till verksamheter som har liknande förutsättningar som fallföretaget. Nyckelord - Varierad efterfrågan, lagerstyrning, säkerhetslagerberäkning, lagerstyrningsmetod. / Abstract Purpose - The purpose of this thesis is to develop an understanding of how to control inventory when the demand varies. To achieve the purpose, the goal is to create a process that facilitates inventory management at varied demand. This is feasible by answering following questions: 1. Which methods of safety stock calculation and inventory control are appropriate and take varied demand in consideration? 2. How is the inventory carrying cost and ordering cost affected by different methods of controlling inventory when demand varies? Method - Information about controlling inventory at varied demand was gathered through literature studies. A case study was carried out to apply the theoretical framework on empirical data from the business case. The empirical data was collected through interviews and documentation studies, which provided a basis for calculation and further analysis. Findings - SERV2 is considered as an appropriate method for safety stock calculations since it takes the number of occasions for shortages into account and provides a good measurement of the stock availability over time. The dynamic inventory control methods Silver &amp; Meal and Wagner-Whitin can handle variations in demand better than order point systems. Calculations show that Wagner-Whitin generates the lowest total costs in the majority of cases. A process is established to facilitate inventory management at varied demand. Implications - Within this study it is shown that using dynamic inventory control methods can reduce inventory control costs when demand varies. Nonetheless it is important to have persuasive input to generate reliable results. Limitations - The dynamic inventory control methods balance order cost with inventory carrying costs to find the most economic option from an inventory control perspective. It is not always the best solution from a holistic perspective since changed order quantities can affect other parts of the material flow. The established process charts are based on chosen solution, which limits its application to businesses with similar conditions as the case study. Keywords - Varied demand, inventory control, safety stock calculation, inventory management

Globalization and increased product variety have impacted the uncertainty in demand and supply. The recent financial instability adds another layer of uncertainty regarding financing and investment. The changes, while gradual, have accumulated over time and posed enormous difficulties in planning procurement. This thesis focuses on inventory procurement strategies that help firms tackle challenges due to uncertainties in the demand/supply and financial concerns. The first part is on employing dynamic inventory procurement strategies to achieve cost efficiency and tackle the uncertainties in demand and supply. The second and third parts focus on the interaction between Finance and Operations in both its analytic aspects and empirical aspects. A synopsis of the three parts of the thesis follows. Part 1: “Inventory Management and Stochastic Lead Time” This chapter analyzes a continuous time back-ordered inventory system with stochastic demand and stochastic delivery lags for placed orders. This problem in general has an infinite dimensional state space and is hence intractable. We first obtain the set of minimal conditions for reducing such a system’s state space to one-dimension and show how this reduction is done. Next, by modeling demand as a diffusion process, we reformulate the inventory control problem as an impulse control problem. We simplify the impulse control problem to a Quasi-Variation Inequality (QVI). Based on the QVI formulation, we obtain the optimality of the (s, S) policy and the limiting distribution of the inventory level. We also obtain the long run average cost of such an inventory system. Finally, we provide a method to solve the QVI formulation. Using a set of computational experiments, we show that significant losses are incurred in approximating a stochastic lead time system with a fixed lead time system, thereby highlighting the need for such stochastic lead time models. We also provide insights into the dependence of this value loss on various problem parameters. Part 2: “Inventory Financing and Trade Credit” In this chapter, we study the inventory performance of publicly listed retailers between 1980 and 2010 based on a panel dataset from COMPUSTAT, CRSP, I/B/E/S and a hand-collected dataset on bankruptcy. We quantify the effect of a carefully-defined financial holding cost on inventory decisions, after controlling for operational factors and considering access to trade credit. This finding provides empirical evidence of the failure of the Modigliani-Miller Theorem in the inventory management context. We are also able to infer several unobservable costs based on historical inventory decisions. For example, the average cost of trade credit is estimated to be about 20% per year, which matches the typical trade credit terms in the United States. We find that the cost of trade credit computed has a strong connection to inventory per- formance. Our findings are robust to alternative econometric specifications, alternative measures of variables and model estimates for subsets of data. Part 3: “Joint Inventory and Cash Management Decisions” In this chapter, we address this question by considering a general con- tinuous time model of a dynamic inventory system that incurs costs in both managing the inventory and managing the cash flow. To support its inventory and operational cost, this system has access to both the financial market and trade credit from suppliers. We show how the inventory procurement decision and financing decision are made jointly. Specifically, we show that, with friction of financing, not only does the Modigliani-Miller Theorem not hold but also the two decisions interact in a dynamic and complex manner. We are also able to show how the value of the inventory system can be improved by using trade credit. / text

Today many companies face problems with inventory management. The importance of adequate inventory management has become more evident, while organizations try to reduce their costs and increase their service level. This master thesis was conducted at VSM Group AB in Huskvarna, which is a manufacturer that produces and delivers sewing machines to a worldwide market. VSM Group AB has problems with the management and the refilling of the work-in-process (WIP) inventories and also with lack of information about component balance and location in the production and material planning system. Therefore, the purpose of the thesis was to improve the control of the WIP inventories and the information about the components in the production and material planning system. In order to achieve the purpose, interviews and observations were performed, theories in inventory management were reviewed and the production process was studied. Afterwards solutions for improvements were proposed. To solve the management and refilling problem, a kanban ordering system was proposed, which would use kanban cards to order components from the storages to the WIP inventories. To develop the component information displayed in the production and material planning system, an additional feature was proposed to the system. So instead of showing one inventory balance for each component, the system would display balances for three different places in the factory: the goods arrival and quality control area, the storage and the production. The proposed solutions can provide several benefits to the company. The kanban ordering system can increase the material handlers’ efficiency, set a standard refilling quantity and be a tool for reducing the WIP inventory levels. The more detailed information in the production and material planning system can improve the decision making for the purchasers and planners and give the ability to measure the flow and level of material inside the factory. These solutions will provide a more appropriate inventory management to the company, with better control of the components and improved information quality.

Finansų rinkų programos Verslo nuosavybės ekonomikos specializacijos magistro baigiamojo darbo tema yra aktuali, nes atsargų valdymas, efektyvus atsargų valdymo proceso organizavimas yra aktualus kiekvienai įmonei, užsiimančiai gamybine ar prekybine veikla. Atsargos – vienas iš įmonės veiksnių jos pelningai veiklai palaikyti. Atsargų valdymas yra jų optimalaus kiekio paieška bei tinkamiausio santykio tarp naudos ir išlaidų išlaikymas. Tyrimo objektas – atsargų valdymas. Pagrindinis šio darbo tikslas – nustatyti, kokia įtaką įmonės pelningumui daro efektyvus atsargų valdymas. Tikslui pasiekti buvo iškelti šie uždaviniai: 1. susipažinti su atsargų rūšimis; 2. atsargų poreikio nustatymas; 3. apibrėžti pagrindinius atsargų įkainojimo metodus; 4. atlikti atsargų panaudojimo efektyvumo analizę. Tyrimo metodika. Darbe naudota mokslinės, ekonominės literatūros analizė apie atsargų valdymą ir su juo susijusias problemas, turto panaudojimo efektyvumo koeficientų analizė. Šiuo darbu norime pagrįsti hipotezę, kad efektyvus atsargų valdymas padidintų įmonės pinigų srautus, kas leistų juos panaudoti verslo plėtrai ar veiklos procesų efektyvumui gerinti. Pirmoje darbo dalyje išanalizavime, kas tai yra atsargos, išnagrinėjome atsargų rūšis ir jų klasifikavimą. Atsargos – trumpalaikis turtas (žaliavos ir komplektavimo gaminiai, nebaigta gamyba, pagamint produkcija bei pirktos prekės, skirtos perparduoti), kurį įmonė sunaudoja pajamoms uždirbti per vienus metus arba per vieną įmonės... [toliau žr. visą tekstą] / Master‘s work in business property economics is actual, because the inventory management, the effective inventory organizing is actual for each producing and trade company. Inventory is one from the most important factors for profitable activity of company. Inventory management is the most suitable relation between the profit and expenses. The object is inventory management. The aim of this article is to research the effective inventory management influence for company’s profitableness. To reach this goal we resolved such tasks as: 1. Become acquainted with qualities of inventory; 2. To define the basic estimation methods; 3. To carry out the analyze of the effective inventory employment. In this article we want to ground the hypothesis that effective inventory management increase profit of company. In the first part we have analyzed the inventory qualities and classification. Inventory is the short-term assets (raw materials and consumables, work in progress, finished products and goods for resale), which company used for receipts earn during one year. Raw materials and consumables, work in progress and finished products are the inventory of producing company. And the goods for resale are the inventory of trade company. In the second part we analyzed the basic estimation methods. The choosing of the estimation methods is one from the most important factors for profitable activity of company, which could influence the sale cost price. For the calculating of used in production... [to full text]

Įmonių praeities pasiekimai yra menkaverčiai dėl dabartinės rizikos veiksnių, rinkos nepastovumo, ekonominio neapibrėžtumo. Šiuolaikinių įmonių dominavimas rinkoje remiasi logistine sistema, gebančia prisitaikyti prie aplinkos pokyčių, gebančia balansuoti tarp „sveiko proto“ ir greito, operatyvaus reagavimo laiku į besikeičiančią pasaulinę verslo aplinką. Tai įpareigojo įmones ieškoti naujų veiklos efektyvumo didinimo būdų ir paskatino verslą atsigręžti į aprūpinimą bei aprūpinimo sistemų valdymą. Šiuo metu aprūpinimo valdymo problemų sprendimas yra vienas iš dažniausiai nagrinėjamų klausimų įmonėse ir organizacijose. Šio darbo tikslas: išnagrinėti mokslinius šaltinius aprūpinimo tema ir išsiaiškinti aprūpinimo reikšmę šiuolaikiniam verslui. Darbe buvo atlikta UAB „Sander Baltic“ aprūpinimo sistemos analizė, norint suformuluoti ir pateikti projektinį sprendimą įmonės aprūpinimo sistemos veiklos tobulinimui. Magistrinis darbas susideda iš trijų dalių. Pirmoje darbo dalyje yra nagrinėjama aprūpinimo reikšmė ir vaidmuo šiuolaikiniame versle. Aptarta aprūpinimo samprata, aprūpinimo sistemų taikymo ypatumai bei problemos. Antroje dalyje pateikiama UAB „Sander Baltic“ aprūpinimo sistemos analizė. Įmonės veiklos specifika yra labai svarbus aspektas numatant tolesnes aprūpinimo sistemos tobulinimo kryptis, kurios yra pateikiamos trečiojoje darbo dalyje. Pastarojoje dalyje taip pat yra analizuojami atlikto tyrimo rezultatai, vertinantys esamą aprūpinimo sistemą ir nurodantys jos... [toliau žr. visą tekstą] / Achievements of the past became of low value in the context of nowadays risk factors, instability of the market, economical indeterminacy. Domination of the companies in the market is now based upon the logistics system capable of adapting to external changes, capable of balancing between rational thinking and timely rapid response to the changing environment of the global trade. This obliged the companies to search for new ways of increasing efficiency and encouraged them to spotlight the supply and supply system management. Solving the problems related to supply management is one of the biggest concerns of the companies and organizations nowadays. The goal of this work: to analyze the scientific articles dealing with the supply topic and to determine the significance of supply to the modern trade. The supply system analysis of company “Sander Baltic” Ltd. has been performed with goal to formulate and propose project solution of company’s supply system improvement. Master degree thesis consists of three parts. In the first part of the work importance and role of the supply in modern trade is analyzed. Conception of supply, peculiarities and problems of supply systems are discussed. The supply system analysis of company “Sander Baltic” Ltd. is presented in the second part of the work. Peculiarity of the company work is very important aspect in scheduling directions of supply system improvement which are presented in the third part of the work. Results of the research... [to full text]

Turint įmonėje ar organizacijoje tam tikrus svarbius išteklius ar objektus, visuomet kyla poreikis juos inventorizuoti, sekti jų judėjimą, kaitą, būsenas ir kitą su jais susijusią informaciją. Įmonių veikloje turimas inventorius turi būti apskaitomas ne tik patogumui užtikrinti, bet yra būtinas tinkamam įmonės darbo organizavimui. Šio darbo tikslas – sukurti įmonės informacinės sistemos inventoriaus apskaitos, kiekvieno įrenginio migravimo sekimo ir atliktų darbų istorijos valdymo sistemą, kuri būtų nepriklausoma nuo operacinės sistemos ir galėtų būti valdoma mobiliuoju įrenginiu. Darbe išanalizuotos rinkoje esančios inventoriaus valdymo sistemos, nurodyti jų privalumai ir trūkumai. Aprašyti įrankių bei serverių pasirinkimo kriterijai. Taip pat pateikti įmonės informacinės sistemos inventoriaus valdymo sistemos projektavimo etapai: sistemos architektūra, duomenų srautai, duomenų bazė, sistemos paketai bei jų tarpusavio ryšiai, kurie remiasi atlikto tyrimo sistemos architektūros savybių pasirinkimui įvertinti rezultatais. Šio darbo metu sukurta sistema jau yra naudojama užsakovo įmonėje ir tenkina visus užsakovo iškeltus reikalavimus jos panaudojimui ir funkcionalumui. Tačiau ši sistema yra lanksti ir gali būti taikoma ir kitų įmonių informacinės sistemos inventoriaus valdymui. / With the company or organization in a number of important resources or objects, is always a need to inventory, track their movement, change, states and other related information. Business inventory is available to be accounted for not only convenience, but it is essential for the proper organization of the company's work. The aim of this work - to create enterprise information systems inventory accounting, tracking each device migration and done job history management system that is independent of the operating system and can be controlled by a mobile device. The paper analyzes the market for existing inventory management system and points out their advantages and disadvantages. There are also described the tools and servers selection criteria. It also provides enterprise IT management system design phases: architecture, data flows, data base, system packages and their mutual relations, which are based on a study of the characteristics of the system architecture choice results. The developed system is already being used in company client and client meets all the requirements raised by its use and functionality. However, this system is flexible and can be applied to other companies’ information systems inventory management.