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Klimatförändringen är en viktigt fråga som kräver insatser inom flera sektorer för att hållbara nivåer på växthusutsläppen ska kunna nås. En av dessa sektorer är livsmedelsindustrin där konsumtionen av livsmedel för en genomsnittlig svensk konsument utgör ca 25 % av de totala utsläppen. En förbättringsmöjlighet inom detta område är minskning av matsvinn. Denna studie fokuserar på hur ökad medvetenhet kring sitt inventarie av livsmedel inom hushåll kan bidra till minskat matsvinn samt hur man på bästa sätt kan designa ett system i detta syfte. För studien utvecklades ett digitalt inventariesystem i form av en uppkopplad skanner för inläsning av streckkoder samt en webbapplikation anpassad till mobila enheter där det aktuella inventariet presenteras tillsammans med en inköpslista. En testgrupp på åtta stycken deltagare fördelat på fyra hushåll fick under en två veckors lång period använda systemet. Efter studien fick de även delta på en intervju om deras upplevelse av- och motivation till att använda systemet, där kvalitativ data samlades in. Den grundläggande teorin bakom studien består primärt av The Behaviour Change Wheel som användes under designprocessen för det framtagna systemet då systemet skulle kräva en beteendeförändring. Resultatet visade en positiv inställning till systemet, där alla medverkande testpersoner ansåg att systemet skulle kunna bidra till minskat matsvinn i hushållen. Resultatet visade även att systemet underlättade kunskapsökning kring användarens inventarie av livsmedel. Det nya beteendet övergick till rutin hos majoriteten av testpersonerna och även fast en del nya funktioner och förbättringar önskades, kunde även majoriteten tänka sig att använda systemet i efterhand. Denna studie är dock i sig för kort för att kunna dra några konkreta slutsatser kring de bestående beteendeförändringar till användningen av systemet. / The climate change is an important issue that requires efforts in several sectors in order to achieve sustainable levels of greenhouse emissions. One of these sectors is the food industry, where the consumption of food for an average Swedish consumer constitutes about 25 % of the total emissions. An opportunity for improvement in this area is the reduction of food waste. This study focuses on how increased awareness of their inventory of household food can contribute to reduced food waste and how to best design a system for this purpose. For the study, a digital inventory system was developed in the form of a barcode scanner and a web application adapted to mobile units where the current inventory is presented together with a shopping list. A test group of eight participants divided into four households received a system during a two-week period. After the study, they also had to attend an interview about their experience of motivation to use the system, where qualitative data was collected. The basic theory behind the study consists primarily of The Behavior Change Wheel which was used during the design process of the system that were developed, since the system would require a behavioral change. The result showed a positive attitude towards the system, where all participating test persons considered that the system could contribute to reduced food waste in households. The result also showed that the system facilitated knowledge raising around the user's food inventory. The new behavior changed to routine with the majority of the test persons and even though some new functions and improvements were desired, the majority could also imagine using the system afterwards. However, this study is in itself too short to be able to draw any concrete conclusions about the permanent behavioral changes to the use of the system. / Smarta förvaringslösningar i framtidens kylskåp för minskat matsvinn

Approved for public release; distribution in unlimited. / Management of the Naval integrated supply system depends on data to provide reliable information on the quantities of items in stock at any given time. Because of the high volume of transactions that continually alter data in the inventory system, inventory record errors are practically unavoidable. The purpose of this thesis is to determine the effects of inventory data errors on both cost and effectiveness of operations at a Naval inventory site. The methodology adopted for research consists of a series of multiple-item, single-warehouse, Monte Carlo simulations, focused on one U.S. Navy inventory site, using estimates of inventory data accuracy obtained at that site. Results of the simulations show that inventory costs can be decreased and customer demand effectiveness increased by decreasing the magnitude of inventory record errors to less than ten percent. It is therefore recommended that the Navy expand its inventory accuracy goal to require that no item have an inventory record error magnitude greater than ten percent. Inventory costs and effectiveness in meeting demand for Naval material were not found to be substantially affected by inventory record inaccuracy if the magnitude of error is less than ten percent. / Lieutenant Commander, United States Navy

Increased product proliferation and global competition are forcing companies within the supply chain to adopt new strategies. Postponement is an effective strategy that allows companies to be agile and cost effective in dealing with the dynamics of global supply chains. Postponement centres around delaying activities in the supply chain until real information about the market is available, which reduces the complexity and uncertainty of dealing with a proliferation of products. A two-echelon divergent supply chain entailing a central production facility and N retailers facing stochastic demand is studied within the inventory-distribution system. A periodic review order-up-to strategy is incorporated at all echelons. Unique to the study, five different systems are created and the effectiveness of several postponement strategies (form and transshipment) under various operational settings are compared. The importance of postponement under an integrated supply chain context and its contribution to various sector implementations are also discussed. Simulation is used to analyze the performance of the systems especially with respect to cost, order lead time and the effectiveness of transshipment policies. The study is unique in determining factors that favour one system implementation over another and distinguishing sector requirements that support postponement. In the study, postponement is found to be an effective strategy in dealing with managing item variety, demand uncertainty and differences in review periods in the two echelon supply chain for different experimental settings.

<p>We propose an approximation scheme for single-product periodic-review inventory systems with L-natural-convex structure. We lay out three well-studied inventory models, namely the lost-sales system, the perishable inventory system, and the joint inventory-pricing problem. We approximate the value functions for these models by the class of L-natural-convex quadratic functions, through the technique of linear programming approach to approximate dynamic programming. A series of heuristics are derived based on the quadratic approximation, and their performances are evaluated by comparison with existing heuristics. We present the numerical results and show that our heuristics outperform the benchmarks for majority of cases and scale well with long lead times. In this dissertation we also discuss the alternative strategies we have tried but with unsatisfactory result.</p> / Dissertation

In this study, inventory&ndash / distribution system of a company operating in Fast Moving Consumer Goods (FMCG) industry is analyzed. The system is a multi&ndash / item, two-echelon, divergent inventory&ndash / distribution system with transportation constraints. The warehouses in the system are nonidentical and all of the warehouses are allowed to hold stock. The goal is to achive target customer service levels. Throughout the system, inventory is controlled by echelon stock periodic review (R, S) order-up-to level policy. The problem is the determination of inventory control parameters in the system and effective replenishment of the inventories of many items at regional warehouses under transportation constraints. An approach consisting of three modules operating in a hierarchy is developed to manage the system. The approach calculates the inventory control parameters of the items (order-up-to levels at the regional warehouses and stock allocation fractions) / determines the replenishment periods of the items with the objective of balancing the vehicle requirements among periods and performs the daily replenishment of inventories minimizing the maximum deviation from the inventory policy under transportation constraints. A heuristic approach is adapted from the literature for the inventory control parameter determination part of the approach / an IP model is formulated for the replenishment period scheduling part and a MIP model is constructed for the replenishment process. The proposed approach is simulated with retrospective data of the company and compared with the existing system in the company, in terms of the performance measures defined. Satisfactory results are obtained with the proposed system.

Att inventera är en påfrestande process där anställda samlar in data med en observationsundersökning. Ett exempel är livsmedelsbutiker som skriver ut meterlånga listor inför en lagerinventering där inventeraren anmärker skillnader på de fysiska varorna och vad som står på listorna. Inventering är något som de flesta företag gör men som skiljer sig från bransch till bransch. Eftersom det är ett resursslöseri att lösa samma problem flera gånger, utan att återanvända tidigare lösningar, har studenten valt att studera en relativt generell lösning på ett inventeringssystem som ska kunna användas av flera branscher.Syftet med denna studie är därför att studera vilka funktionalitetskrav som finns på ett inventeringssystem och vilka tekniska lösningar som kan användas vid utveckling av ett inventeringssystem.För att utreda detta tillämpades en abduktiv ansats där en fallstudie gjordes på inventering. En litteraturstudie gjordes på tekniska lösningar som kan användas vid utveckling av ett inventeringssystem.Studiens resultat är en kravspecifikation på ett inventeringssystem från lager- och skogsbranschen. Resultatet innehåller även tekniska lösningar som kan tillämpas och därmed uppfylla kraven. Parallellt med studien utvecklades en inventeringsklient tillsammans med Sweco som uppfyller både deras krav på klienten och de krav som studiens empiri erhållit. Resultatet av studien visar på ett system som klarar av att skapa, spara och återskapa dynamiska formulär. När formulär skapas kan dess kontrollelement ha restriktioner som klienten kan validera innan resultat sparas. Studiens resultat visar även på att en förstudie av ett system tenderar till att hitta indirekta/dolda krav.Den primära begränsningen i studien har varit tid. Hade mer tid kunnat ägnas åt studien skulle insamlingen av empiri ha varit mer omfattande. / Stocktaking is an exhausting process where employee’s collects data and is something that most companies do, although what they are collecting differs from business to business. Because it is a resource-waste to solve same problem multiple times, without reusing previous solutions, the student have choosen to study an overall solution for a stocktaking system that can be used by multiple businesses.The purpose of this report is to establish the end-user requirements on a stocktaking system and study which technical solutions can be used when developing a stocktaking system.The study used an abductive method with a case study on stocktaking. For the case study the empiricism was collected with interviews. A meta-analysis was implemented for the purpose to seek and analyse relevant literature.The result of the study was a requirement specification for an inventory system based on the forest and stock industry. The result also contains technical solutions that can be applied on the system in order to fulfill the requirements. In parallel with the study an attempt was made to develop a prototype of a stocktaking client togheter with Sweco that met both their requirements and requirements that was obtained from the interviews. The results show that the stocktaking client can manage to create, save and recreate dynamic forms. When forms are created their controls also have the ability to specify restrictions. The client can interpret these restrictions and validate the inputs before saving results. The results of the study also implies that a feasibility study of a system tend to find hidden requirements.The primary limitations of the study were time. If the study had a larger timescope more time could have been spent on collecting empirical data and gather end-user requirements.

Le « transshipment (latéral) d’urgence » au sein des réseaux de distribution consiste à organiser les transferts de stocks entre les détaillants pour faire face aux situations de rupture. Sa mise en œuvre amène à arrêter une stratégie appropriée et à harmoniser ses paramètres avec la politique et paramètres de gestion des stocks, dans l’objectif de garantir un taux de satisfaction des demandes clients au moindre coût. Le présent travail se situe dans ce contexte et s’est focalisé sur l’analyse des apports de la mise en œuvre du transshipment d’urgence dans un système de pilotage de flux tirés par des demandes clients probabilistes, avec des politiques locales de gestion de stock du type (R, s, S). Notre étude a porté sur trois structures différentes de réseau : système de stock à deux échelons et à deux détaillants, avec coût unitaire de transshipment ; système de stock à deux échelons et à détaillants multiples, avec coût fixe de transshipment ; système de stock multi échelons à deux détaillants, avec coût fixe de transshipment. Pour chacune de ces structures, nous avons analysé le comportement du système pour différentes combinaisons des paramètres d’entrée (délais d’approvisionnement, écarts types de la demande et nombre des détaillants) et des paramètres de coût (commande, possession, rupture et transshipment). Nous avons visé à déterminer, sur un horizon fini de périodes, les seuils de stocks (s et S chez les détaillants et chez le centre de distribution) qui minimisent le coût total du système tout en garantissant un taux de service désiré. Dans ce cadre, quatre politiques de transshipment (« tout ou rien », « complete pooling standard », « complete pooling plafonné » et « complete pooling conditionné ») ont été explorées. L’étude est d’abord ébauchée selon une approche analytique puis approfondie par l’élaboration et l’expérimentation de modèles dont la résolution est basée sur la simulation-optimisation / The lateral emergency transshipment in distribution systems consists in organizing inventory transferts between retailers to face shortage situations. Its implementation leads to adopt an appropriate transhipment policy and harmonize its parameters with inventory policy parameters and inventory control policy. The objective is to ensure a desired service level at minimum cost. Thie work is situated in this context and focused on the analysis of emergency transhipment benefits in distribution systems faced to random customers demand. Each retailer used an (R,s,S) inventory control policy. Our study is related to three different distribution systems structure : two echelons two retailers inventory system with unit transhipment cost; two echelons multi retailers inventory system with fixed transhipment cost; multi echelons multi retailers inventory system with fixe transhipment cost. For each of these structures we analyzed the sensibility of system behaviour to input parameters. Our objective is to determine on a finite horizon the inventory parameters (s, S) that minimize total cost under service level condition.

Research object: stocks. Research subject: accounting and audit. Research aim: to investigate the main problems of stocks accounting and audit and to give suggestions that can help to improve stocks accounting and audit. Objectives: 1)To analyze the peculiarities of stocks and production accounting and audit; 2)To carry out an empirical research of stocks and production accounting and audit; 3)To define and analyze the main problems of stocks and production accounting and audit; 4)To formulate conclusions and suggestions in order to develop the field of stocks accounting and audit; Research methods: logical analysis, synthesis, comparison, questionnaire survey and description. In the process of investigation there were analyzed theory and practice of stocks accounting and audit, investigated the main problems of stocks accounting and audit and also given suggestions that can help to solve investigated problems.

This thesis presents a study of stochastic models of continuous review of inventory systems of perishable and non-perishable products, as well as inventory systems operating in random environment. It contains five chapters. The first chapter is introductory in nature, containing the motivation for the study and the techniques required for the analysis of respective models described in the remaining chapters. Chapter 2 provides a model of perishable product inventory system operating in a random environment. For the sake of simplicity, the stochastic environment is considered to alternate randomly over time between two states 0 and 1 according to an alternating renewal process. When the environment is in state k, the items in inventory have a perishable rate ìk, the demand rate is ëk and the replenishment cost is CRk. The performance of various measures of the system evolution are obtained, assuming instantaneous replenishment at the epoch of the first demand after the stock-out and associating a Markov renewal process with the inventory level. In Chapter 3, a continuous review single product perishable inventory model is considered. Items deteriorate in two phases and then perish. Independent demands occur at constant rates for items in phase I and in phase II. Demand that occurs for an item in phase I during its stock-out period is satisfied by an item in phase II with some probability. However a demand for an item in phase II occurring during its stock-out period is lost. The reordering policy is an adjustable (S,s) policy with the lead-time following an arbitrary distribution. Identifying the stochastic process as a renewal process, the probability distribution of the inventory level at any arbitrary instant of time is obtained. The expressions for the mean stationary rates of demands lost, demands substituted, perished units and scrapped units are also derived. A numerical example is considered to highlight the results obtained. Chapter 4 is a study of a two-commodity inventory system under continuous review. The maximum storage capacity for the i-th item is Si (i=1, 2). The demand points for each commodity are assumed to form an independent Poisson process, with unit demand for one item and bulk demand for the other. The order level is fixed as si for the i-th commodity (i=1, 2) and the ordering policy is to place an order for Qi (= Si – si , i = 1,2) items for the i-the commodity when both the inventory levels are less than or equal to their respective reorder levels. The lead-time is assumed to be exponential. The joint probability distribution for both commodities is obtained in both transient and steady state cases. Various measures of systems performance and the total expected cost rate in the steady state are derived. The results are illustrated with numerical examples. Chapter 5 provides an analysis of a continuous review of two-product system with two types of demands and with individual (S,s) ordering policy. The lead-time distribution of product 1 is arbitrary and that of product 2 exponential. Two types of demands occur at constant rates either for both products or for product 2 alone. Expressions for the stationary distribution of the inventory level are obtained by identifying the underlying stochastic processes as a semi-regenerative process. The mean stationary rates of the lost demands, the demands that are satisfied and the number of reorders are obtained and these measures are used to provide an expression for the cost rate. The main objective of this thesis is to improve the state of art of continuous review inventory systems. The salient features of the thesis are summarized below: <ul>(a) Consideration of</ul> <ul>(i) The impact of the stochastic environment on inventory systems;</ul> <ul>(ii) The interactions existing among the products in multi-product systems;</ul> <ul>(iii) Individual and joint-ordering policies;</ul> <ul>(b) Discussion of inventory systems with perishable products; </ul> <ul>(c) Effective use of the regeneration point technique to derive expressions for various system measures;</ul> <ul>(d) Illustration of the various results by extensive numerical work;</ul> <ul>(e) Relevant optimization problems</ul> / Thesis (PhD (Industrial Engineering))--University of Pretoria, 2006. / Industrial and Systems Engineering / unrestricted