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

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.

We study an inventory system with two potential supply modes: regular order placement opportunities happen at a fixed frequency, which defines regular review cycles, while emergency orders can be placed on every period within a regular review cycle. Regular and emergency orders incur a per-unit cost while the latest incurs an additional setup cost For a regular order lead-time equal to two periods, we show that the optimal policy with respect to the expected total discounted cost, is of (s; S) type for emergency orders while the size of a regular order depends on the inventory position following a potential emergency order. Although we could not establish the optimality for regular order lead-times exceeding two periods, substantial experimental evidence supports the conjecture that the optimal policy retains the same structure. Since the optimal policy algorithm requires significant computational effort, we develop and evaluate two heuristic policies whose operational parameters can be computed with relatively small computational effort and compare them against the optimal policy in terms of implementation difficulty, speed and accuracy for an experimental design of 3888 cases. The evaluation of the proposed optimal policy and the two heuristics requires a simulation suite flexible enough to capture the specific problem dynamics. This motivates the development of the Inventory Simulator Workbench (ISW). This inventory system simulator, written in Java, provides the user with a graphical interface and the ability to model a large range of supply chain structures and inventory ordering and distribution policies.

Thesis--Universität St. Gallen, 2005. / Description based on print version record. Includes bibliographical references (p. 192-208).

Thesis (Ph.D. in counseling)--Liberty University, 2006. / Includes bibliographical references.

Thesis (MCIS - Computer and Information Sciences)--AUT University, 2007. / Includes bibliographical references. Also held in print (vii, 94 leaves ; 30 cm.) in the Archive at the City Campus (T 658.514 ZHA).

Dissertation--Universitat St. Gallen, 2005. / Includes bibliographical references (p. 192-208). Also available in print.

The demand from modern day customers for quality products, supplied in any quantity and within a short lead-time, forces organisations to stock the correct amount of inventory in the correct locations in its supply chain. Establishing the correct inventory levels within an organisation’s supply chain is complicated by the various stochastic processes occurring in a supply chain. The thesis is aimed at the development of a generic Just-In-Time (JIT) supply chain optimisation software tool, whereby the correct inventory levels for an organisation can be determined. These inventory levels will ensure that the organisation will achieve a predefined customer service level at the minimum cost to the company. The tool was developed and satisfactory results were obtained using the Harmony Search Algorithm (HSA) for optimising the inventory levels.

Syftet med den här rapporten har varit att undersöka möjligheterna att automatisera själva inventeringsarbetet med hjälp av drönare. Rapporten ska lyfta fram vilka kravspecifikationer en drönare skulle behöva uppfylla för att detta ens skulle kunna vara möjligt överhuvudtaget samt undersöka på vilket sätt detta kan medföra effektivisering av inventeringsprocessen och minimera risk för olyckor. Rapportens uppbyggnad består utav att olika kravspecifikationer presenteras enskilt från drönaren i den teoretiska referensramen som sedans knyts samman i analysen där författarna presenterar de utvalda kravspecifikationerna som kan anses vara mest lämpliga, baserat på vald teori, empiri och avgränsningsområdet. För att kunna besvara vårt syfte så fanns det en del frågeställningar som behövde svar, där fyra företag intervjuades. Med dessa frågor kunde det skapas en uppfattning kring hur inventeringsprocessen såg ut hos olika företag idag och vilka svårigheter man upplevde i samband med processerna. Det noterades snabbt att alla involverade företagen upplevde gemensamma problem vid sina inventeringsprocesser och ansåg att en automatiserad lösning var något att vänta sig inom en snar framtid. De ansåg att inventeringsprocessen var tidskrävande och en icke värdeskapande aktivitet där man kunde lägga resurserna på annat. Trots att inventeringen ansågs vara icke värdeskapande, så är det fortfarande en aktivitet som måste utföras delvis för lagkrav men även för att kunna behålla hög service nivå och leveransförmåga. Vidare lyfts det fram i rapporten hur en möjlig körplan med drönare kan se ut, hur denna möjligtvis kan effektivisera arbetet och den reducering av risk för olyckor som sker på gods och personal i samband med inventeringen. Författarna anser att tekniken för att kunna uppnå detta finns tillgänglig, utan det handlar mer om hur man använder tekniken och utformar miljön som drönaren ska verka i för att det ska bli så optimalt som möjligt. Vidare drogs slutsatsen att det kommer att ta tid tills detta kan helautomatiserats och kommer till en början behöva kompletteras med stöd från den mänskliga faktorn. / The purpose of this report has been to investigate the possibilities of automating the inventory process with the help of drones as well as investigating how this can make the inventory process more efficient. Furthermore, the report will highlight the specifications that a drone would have to meet in order for this to be possible at all, as well as investigate how this could lead to a more effective inventory process and minimizing the risk of accidents that occurs during the inventory process. The structure of the report consists of different specifications that are presented where the authors selected requirement specifications which are considered most suitable based on the chosen theory and empirical studies. In order to answer the purpose of this assignment, there were a few questions that needed some research in order to find relevant answers where four companies were interviewed. With these questions, we would be able to get an idea of ​​how the inventory process looked at different companies and what difficulties they experienced in the processes. All the interviewed companies often experienced common problems in their inventory processes and told the authors that an automated solution was something to be expected in the near future. Furthermore, they considered that the inventory process was time-consuming and a non-value-creating activity where one could put the resources elsewhere if there was a drone able to perform the expected work because of, despite the fact that the inventory was considered to be non-value-creating, it is still an activity that must be performed since it is a legal requirement, but also to maintain a high level of service and good delivery ability. Furthermore, a plan for how the drone should work is presented and how it possibly would make the inventory process more effective and minimize the risk of accidents that can occur on goods and staff. The authors believe that the technology for achieving this is available, but it is more about using the technology and designing the warehouse to make this as optimal as possible. Furthermore, the authors believe that it will take time until it can be fully automated and will initially, have to be supplemented with support from the human factor.

This master thesis deals with methods of stocktaking in various enterprises. The aim of the thesis is to describe methods of inventory taking, to define basic problems and to provide recommendations to solve them. In the introductory of the theoretical part the characteristics of stocktaking, its preparation are described. Secondly the main specifics of conducting inventory taking (regular stocktaking, cash audit, and partial stocktaking) and interception of stocktaking differences in accounting and tax impacts are recounted. The application part consists of research via questionnaire and the aims were to pick out the general problems and to compare them with the recommendations in professional literature. The analysis indicates that the especially small companies underestimate the preparation of stocktaking and that the strenuousness of inventory taking rises with the size of a company. As the complementary method the interview in two companies was chosen, generally speaking the results affirms the results of questionnaire research.