This thesis work aims to improve the stock management system of Excillum AB, a Stockholm-based company that specializes in high-performance X-ray sources. The current stock management system has limitations, resulting in gaps when managing the inventory. To address this, the study focuses on developing a calculation model that takes into account various factors such as the global supply chain, customer expectations, service offerings, and financial concerns. The research questions revolve around understanding best practices in stock management from other companies, considerations for stock selection and ordering decisions, and additional parameters to ensure accurate safety stock calculations. The research involves carrying out a literature review, benchmarking practices from other organizations, analyzing Excillum's transaction data, and developing a reliable calculation model. However, some limitations exist, such as relying on Excel for calculations rather than changing values within the ERP system, which reduces demand projection accuracy due to high product customization. Human factors and unavoidable supply chain disruptions are not specifically addressed in the recommended approach. The proposed calculation model aims to improve stock management efficiency, ensure product availability, reduce stockouts, and ultimately contribute to Excillum's growth goals while meeting customer demands. Excillum can optimize stock levels and streamline inventory management by incorporating best practices and taking into account critical factors, establishing the way for long-term success and improved customer satisfaction. / Detta examensarbete syftar till att förbättra lagerhanteringssystemet för Excillum AB, ett Stockholmsbaserat företag som är specialiserat på högpresterande röntgenkällor. Det nuvarande lagerhanteringssystemet har begränsningar, vilket resulterar i luckor vid hanteringen av lagret. För att komma till rätta med detta fokuserar studien på att utveckla en beräkningsmodell som tar hänsyn till olika faktorer såsom den globala leveranskedjan, kundernas förväntningar, tjänsteerbjudanden och ekonomiska problem. Forskningsfrågorna kretsar kring att förstå bästa praxis inom lagerhantering från andra företag, överväganden för aktieval och beställningsbeslut och ytterligare parametrar för att säkerställa korrekta beräkningar av säkerhetslager. Forskningen innebär att man genomför en litteraturgenomgång, benchmarking praxis från andra organisationer, analyserar Excillumstransaktionsdata och utvecklar en tillförlitlig beräkningsmodell. Det finns dock vissa begränsningar, som att förlita sig på Excel för beräkningar snarare än att ändra värden inom ERP-systemet, vilket minskar noggrannheten i efterfrågeprojekteringen på grund av hög produktanpassning. Mänskliga faktorer och oundvikliga störningar i försörjningskedjan behandlas inte specifikt i den rekommenderade metoden. Den föreslagna beräkningsmodellen syftar till att förbättra lagerhanteringseffektiviteten, säkerställa produkttillgänglighet, minska lagerutbudet och i slutändan bidra till Excillumstillväxtmål samtidigt som kundernas krav tillgodoses. Excillum kan optimera lagernivåer och effektivisera lagerhantering genom att införliva bästa praxis och ta hänsyn till kritiska faktorer, etablera vägen för långsiktig framgång och förbättrad kundnöjdhet.

M. Tech. (Department of Process Control and Computer Systems, Faculty of Engineering and Technology), Vaal University of Technology. / Radio Frequency Identification Technology (RFID) technology is increasingly being used in multiple applications due to its low cost and ability to provide a high quality of identification. The cost benefit of RFID system is seen in the reduction in labor required to perform routine tasks such as inventory. With RFID, inventory-related tasks can be done in substantially less time compared to other commonly used auto-identification systems. Recent research has illustrated the application of RFID in multiple application scenarios. RFID can be used for real-time patient identification and monitoring in hospitals, but also for product expiration-date management in retail industries. Some enterprises in South Africa uses a combination of RFID technology and Internet of Things (IoT) to detect misplaced products and to detect low stock levels. Furthermore, RFID is also used for inventory management in libraries as discussed in this dissertation. In this dissertation, a combination of RFID and ZigBee technologies was used to reduce the time spent to perform inventory in libraries. An inventory management system was designed, simulated and built in order to count and locate books inside a library hence improving inventory process time in libraries. The overall results were satisfactory which lead to the achieving of the objectives set in this study.

Tesis por compendio / [ES] La gestión sostenible de las cadenas de suministro se ha transformado en un tema de alto interés entre profesionales e investigadores en el ámbito de la ingeniería industrial. El impacto que generan las actividades económicas en el medioambiente y en las comunidades donde éstas se ubican ha generado un incremento en el desarrollo de herramientas que permitan incorporar dichos impactos en las decisiones tomadas en el nivel estratégico de las empresas e industrias. Es así como surgen nuevos paradigmas respecto al modelo de producción, como por ejemplo la economía circular, donde se busca transitar desde una economía de producción lineal, hacia una circular reduciendo al mínimo la generación de desperdicios, ya sea material y/o energético. En este contexto, esta tesis doctoral, sustentada en una revisión de la literatura y en un análisis de modelos de optimización matemática de referencia, propone un marco conceptual como herramienta de soporte para seguir desarrollando modelos cuantitativos para dar soporte a los problemas de localización, inventario y transporte (LIT) en cadenas de suministro sostenibles, así como, un modelo de optimización multiobjetivo no lineal entero mixto (MOMINLP) para diseñar una cadena de suministro sostenible de bucle cerrado considerando las decisiones LIT, donde los aspectos de sostenibilidad: económico, medioambiental y social son incorporados en cada una de las decisiones anteriores. El modelo propuesto, denominado 3S-LIT, considera cuatro funciones objetivo que pretenden: (1) minimizar el coste total de la cadena de suministro; (2) minimizar los costes asociados a la emisión de CO2 equivalente; (3) minimizar el coste social relacionado con los accidentes laborales; y (4) maximizar el impacto social, medido como el incremento en cuanto a la generación de empleos directos e indirectos y la reducción en la cantidad de personas afectas por los riesgos del transporte dentro de la cadena de suministro. El modelo 3S-LIT ha sido validado en una empresa del sector minero del cobre obteniendo un mejor desempeño en los valores de las funciones objetivo respecto a los obtenidos en la situación actual. Además, el modelo 3S-LIT se ha comparado con un enfoque existente en la literatura científica obteniéndose unos resultados satisfactorios tanto en términos de funcionalidades como de resultados. Finalmente, el modelo propuesto de optimización matemática, 3S-LIT, es replicado en un modelo de simulación con el cual se estudiaron posibles escenarios de disrupción de la cadena de suministro con el objetivo de analizar su capacidad resiliente. / [CA] La gestió sostenible de les cadenes de subministrament s'ha transformat en un tema d'alt interès entre professionals i investigadors en l'àmbit de l'enginyeria industrial. L'impacte que generen les activitats econòmiques en el medi ambient i en les comunitats on aquestes se situen ha generat un increment en el desenvolupament d'eines que permeten incorporar aquests impactes en les decisions preses en el nivell estratègic de les empreses i indústries. És així com sorgeixen nous paradigmes respecte al model de producció, com per exemple l'economia circular, on se cerca transitar des d'una economia de producció lineal, cap a una circular reduint al mínim la generació de desaprofitaments, ja siga material i/o energètic. En aquest context, aquesta tesi doctoral, sustentada en una revisió de la literatura i en una anàlisi de models d'optimització matemàtica de referència, proposa un marc conceptual com a eina de suport per a continuar desenvolupant models quantitatius per a donar suport als problemes de localització, inventari i transport (LIT) en cadenes de subministrament sostenibles, així com, un model d'optimització multi-objectiu no lineal enter mixt (MOMINLP) per a dissenyar una cadena de subministrament sostenible de bucle tancat considerant les decisions LIT, on els aspectes de sostenibilitat: econòmic, mediambiental i social són incorporats en cadascuna de les decisions anteriors. El model proposat, denominat 3S-LIT, considera quatre funcions objectiu que pretenen: (1) minimitzar el cost total de la cadena de subministrament; (2) minimitzar els costos associats a l'emissió de CO2 equivalent; (3) minimitzar el cost social relacionat amb els accidents laborals; i (4) maximitzar l'impacte social, mesurat com l'increment quant a la generació d'ocupacions directes i indirectes i la reducció en la quantitat de persones afectes pels riscos del transport dins de la cadena de subministrament. El model 3S-LIT ha sigut validat en una empresa del sector miner del coure obtenint un millor acompliment en els valors de les funcions objectiu respecte als obtinguts en la situació actual. A més, el model 3S-LIT s'ha comparat amb un enfocament existent en la literatura científica obtenint-se uns resultats satisfactoris tant en termes de funcionalitats com de resultats. Finalment, el model proposat d'optimització matemàtica, 3S-LIT, és replicat en un model de simulació amb el qual es van estudiar possibles escenaris de disrupció de la cadena de subministrament amb l'objectiu d'analitzar la seua capacitat resilient. / [EN] Sustainable supply chain management has become a topic of great interest among practitioners and researchers in the field of industrial engineering. The impact generated by economic activities on the environment and the communities where they are located has generated an increase in the development of tools that allow the incorporation of these impacts in the decisions taken at the strategic level of companies and industries. This is how new paradigms emerge regarding the production model, such as the Circular Economy, which seeks to move from a linear production economy to a circular one by minimising the generation of waste, both material and energetic. In this context, this PhD thesis, supported by a state-of-the-art study and the analysis of benchmark mathematical optimisation models, presents a conceptual framework to provide the key elements that act as a valuable tool to further develop quantitative models of location, inventory and transport (LIT) problems in sustainable supply chains, and a novel mixed integer non-linear multi-objective mixed integer multi-objective optimisation model (MOMINLP) for designing a closed-loop sustainable supply chain considering location, inventory and transportation decisions, where economic, environmental and social sustainability aspects are incorporated in each of the above mentioned decisions. The proposed model, called 3S-LIT, considers four objective functions that aim to: (1) minimise the total cost of the supply chain, (2) minimise the costs associated with CO2 equivalent emissions, (3) minimise the social cost related to occupational accidents, and (4) maximise the social impact, measured as a higher generation of direct and indirect jobs and a lower number of people affected by transport risks within the chain. The 3S-LIT model has been applied in a company in the copper mining sector, confirming a better performance in the values of the objective functions compared to those obtained in the current situation. In addition, the mathematical optimisation model is replicated in a simulation model with which possible supply chain disruption scenarios were studied to analyse the resilience of the supply chain. / This thesis has been developed within the Research Centre on Production Management and Engineering (CIGIP) of the Universitat Politècnica de València, within the framework of the projects: "Industrial Production and Logistics Optimization in Industry 4.0" (i4OPT) (Ref. PROMETEO/2021/065) granted by the Valencian Regional Government and received funding from Grant RTI2018-101344-B-I00 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”; “Validation of transferable results of optimisation of zero-defect enabling production technologies for supply chain 4.0” (CADS4.0-II) from the grant PDC2022-133957-I00; and by European Union Next GenerationEU/PRTR, and from the European Union’s Horizon Europe research and innovation programme under grant agreement No. 101070076 "Optimizing Production and Logistic Resources in the Time-critical Bio Production Industries in Europe" (CLARUS). It was also funded by the National Agency for Research and Development (ANID)/Scholarship Program/Doctorado Becas en el Extranjero/2020 – 72210174 and sponsored by the Universidad de Atacama as part of an academic improvement plan. / Becerra Muñoz, PA. (2023). Quantitative Models of Location, Inventory and Transportation Decisions for Sustainable Supply Chain Management [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/196651 / Compendio

The central thesis of this dissertation is that by combining classical scheduling methodologies with those of inventory management and queueing theory we can better model, understand and solve complex real-world scheduling problems. In part II of this dissertation, we provide models of a realistic supply chain scheduling problem that capture both its combinatorial nature and its dependence on inventory availability. We present an extensive empirical evaluation of how well implementations of these models in commercially available software solve the problem. We are therefore able to address, within a specific problem, the need for scheduling to take into account related decision-making processes. In order to simultaneously deal with combinatorial and dynamic properties of real scheduling problems, in part III we propose to integrate queueing theory and deterministic scheduling. Firstly, by reviewing the queueing theory literature that deals with dynamic resource allocation and sequencing and outlining numerous future work directions, we build a strong foundation for the investigation of the integration of queueing theory and scheduling. Subsequently, we demonstrate that integration can take place on three levels: conceptual, theoretical and algorithmic. At the conceptual level, we combine concepts, ideas and problem settings from the two areas, showing that such combinations provide insights into the trade-off between long-run and short-run objectives. Next, we show that theoretical integration of queueing and scheduling can lead to long-run performance guarantees for scheduling algorithms that have previously been proved only for queueing policies. In particular, we are the first to prove, in two flow shop environments, the stability of a scheduling method that is based on the traditional scheduling literature and utilizes processing time information to make sequencing decisions. Finally, to address the algorithmic level of integration, we present, in an extensive future work chapter, one general approach for creating hybrid queueing/scheduling algorithms. To our knowledge, this dissertation is the first work that builds a framework for integrating queueing theory and scheduling. Motivated by characteristics of real problems, this dissertation takes a step toward extending scheduling research beyond traditional assumptions and addressing more realistic scheduling problems.

The central thesis of this dissertation is that by combining classical scheduling methodologies with those of inventory management and queueing theory we can better model, understand and solve complex real-world scheduling problems. In part II of this dissertation, we provide models of a realistic supply chain scheduling problem that capture both its combinatorial nature and its dependence on inventory availability. We present an extensive empirical evaluation of how well implementations of these models in commercially available software solve the problem. We are therefore able to address, within a specific problem, the need for scheduling to take into account related decision-making processes. In order to simultaneously deal with combinatorial and dynamic properties of real scheduling problems, in part III we propose to integrate queueing theory and deterministic scheduling. Firstly, by reviewing the queueing theory literature that deals with dynamic resource allocation and sequencing and outlining numerous future work directions, we build a strong foundation for the investigation of the integration of queueing theory and scheduling. Subsequently, we demonstrate that integration can take place on three levels: conceptual, theoretical and algorithmic. At the conceptual level, we combine concepts, ideas and problem settings from the two areas, showing that such combinations provide insights into the trade-off between long-run and short-run objectives. Next, we show that theoretical integration of queueing and scheduling can lead to long-run performance guarantees for scheduling algorithms that have previously been proved only for queueing policies. In particular, we are the first to prove, in two flow shop environments, the stability of a scheduling method that is based on the traditional scheduling literature and utilizes processing time information to make sequencing decisions. Finally, to address the algorithmic level of integration, we present, in an extensive future work chapter, one general approach for creating hybrid queueing/scheduling algorithms. To our knowledge, this dissertation is the first work that builds a framework for integrating queueing theory and scheduling. Motivated by characteristics of real problems, this dissertation takes a step toward extending scheduling research beyond traditional assumptions and addressing more realistic scheduling problems.

L'objectif de cette recherche est de développer des modèles aussi bien conceptuels, analytiques et managériaux en analysant un maillon de la supply chain, à savoir la relation entre un distributeur et deux fournisseurs opérant dans un environnement incertain. Dans la première partie de la thèse, nous considérons un seul produit, plutôt haut de gamme et/ou périssable, et nous faisons l’analyse sur un horizon d’une période. Dans ce cas précis, les caractéristiques unitaires du produit sont toutes non linéaires, à savoir : le prix, le coût de production, le coût de rupture, le coût de reprise. La demande est supposée être une variable aléatoire. Dans la deuxième partie de la thèse, nous nous inspirons des pratiques de firmes internationales qui s’approvisionnent, pour une partie de leur offre, dans des pays à bas coûts. Nous développons plusieurs modèles mais dont la structure de base est similaire, à savoir : deux produits (un haut gamme acheté localement et l’autre bas de gamme acheté dans les pays à bas coûts), un horizon de trois périodes, deux fournisseurs à capacité de production limitée et un distributeur ayant des capacités de stockage limitées. Une panoplie de résultats théoriques, numériques ainsi que des insights sont présentés.Les modèles développés peuvent être utilisés comme des outils d’aide { la prise de décision dans les environnements décrits dans cette thèse / The objective of this research is to develop conceptual, analytical, and managerial models and insights by analyzing a portion of the supply chain made up of a retailer dealing with two suppliers in an uncertain environment. In the first part of this thesis, we consider a single high-end (or perishable) product, single period, variable unit price, variable unit production cost, variable unit shortage cost, variable unit salvagevalue, stochastic demand problem. In a second part of the thesis, we consider settings inspired by the case of large international companies sourcing some of their products from low cost countries. This structure is as follows: two products (one sourced locally and the other sourced abroad), a three-period, two-stages, two capacitated suppliers, and a single capacitated retailer. Both analytical and numerical results are provided. Important theoretical results and insights are developed for these types of settings. These models can be used as decision-making aid tools in such environments

This thesis deals with material management.in CzechPak manufacturing plant. The main aim of the thesis is to analyse the current situation of logistics at CzechPak Manufacturing and propose changes to ease material management. Further aim is to point out key materials and suppliers. The thesis introduces the plant targets and postion of logistic targets within the plant strategy. In this thesis food industry features are specified with regards to logistic processes. The thesis gives proposals for process and system changes in material management with taking advantages of SAP system. In this thesis ABC analysis is applied on materials in CzechPak Manufacturing to indicate key materials and propose supplies optimization.

No description available.

The purpose of the work is to develop recommendations for the improvement of methods and organization of enterprise logistics support system. The theoretical bases of the procurement activities of industrial enterprises were surveyed in this work; the practice of procurement management on the example of OJSC Sinara Pipe Plant was investigated; shortcomings and weak points in the theoretical, methodological and organizational framework of the logistics support were revealed; recommendations to improve the efficiency of supply by necessary materials and resources for enterprise were developed. Organizational and methodical ways to improve the enterprise logistics support system were proposed:  a way of improving the system of classification of resources on the most significant economic and technical characteristics and classification system for their storage were offered;  the changing of the supply department organizational structure was offered to improve its efficiency: the introduction of a new post of specialist in the nomenclature of used material resources to ensure uniqueness in the naming and classification of resources;  a method of suppliers rating was developed;  the technique of identifying illiquid stocks, reducing their level and to prevent further accumulation was developed. / Цель работы заключается в разработке рекомендаций по совершенствованию методов и организации обеспечения материально-технического снабжения предприятия. В работе раскрыты теоретические основы закупочной деятельности промышленного предприятия; исследована практика организации закупочной деятельности на примере ОАО СинТЗ; выявлены недостатки и проблемные места в теоретических, методических и организационных основах материально-технического обеспечения предприятия; разработаны рекомендации, направленные на повышение эффективности процесса снабжения предприятия необходимыми материалами и ресурсами. Предложены организационные и методические пути совершенствования системы снабжения предприятия:  предложен путь усовершенствования системы классификации ресурсов по наиболее значимым экономическим и техническим классификационным признакам и системы их складирования;  предложено изменение организационной структуры отдела снабжения для повышения эффективности его работы: введение новой должности специалиста по номенклатуре используемых материальных ресурсов с целью обеспечения однозначности в наименовании и классифицировании ресурсов;  разработана методика рейтинговой оценки поставщиков;  предложена методика выявления неликвидных запасов, снижения их уровня и предотвращения их дальнейшего накопления

The dairy industry is a complex system that involves many stakeholders and processes, from production to distribution. To measure and improve the performance of this system, a comprehensive and reliable Performance Measurement System (PMS) is needed. A PMS is a tool that helps to evaluate the efficiency and effectiveness of supply chain operations. One of the components of a PMS is the key performance indicators (KPIs), which reflect the performance of specific aspects of the supply chain. This thesis explores how KPIs can be used to enhance logistics performance in the dairy industry. The research is based on a single case study of a global company that operates in the dairy sector, which faces challenges such as high competition, customer demand variability, and food waste. The research uses a mix of literature review, interviews, and data analysis to identify and evaluate the relevant KPIs for logistics performance, as well as their interrelationships and impacts. The research applies the interpretive structural modeling (ISM) method to develop a hierarchical model of the KPIs and their causal relationships. The interpretive structural model of the indicators shows that the current indicators commonly used in the dairy industry today are not suitable for measuring performance, the indicators do not affect the current performance significantly but rather reflect the. This paper proposes a methodology for qualitatively evaluating performance measures, based on the integration of the ISM approach, the MICMAC analysis, and the seven criteria of a KPI. The ISM approach is a technique for identifying and analyzing the interrelationships among elements of a complex system. By applying this methodology, organizations and researchers can assess the suitability and importance of a set of KPIs. / Mejeriindustrin är ett komplext system som involverar många intressenter och processer, från produktion till distribution. För att mäta och förbättra systemets prestanda behövs ett heltäckande och tillförlitligt system för prestationsmätning (PMS). Ett PMS är ett verktyg som hjälper till att utvärdera effektiviteten i leveranskedjans verksamhet. En av komponenterna i ett PMS är nyckeltal (KPI:er), som är mått som återspeglar prestandan för specifika aspekter av leveranskedjan. Denna studie syftar till att undersöka hur KPI:er kan användas för att förbättra logistiken inom mejeriindustrin. Forskningen baseras på en fallstudie av ett globalt företag som är verksamt inom mejerisektorn, som står inför utmaningar som hög konkurrens, varierande kundefterfrågan och matsvinn. Forskningen använder en blandning av litteraturstudier, intervjuer och dataanalys för att identifiera och utvärdera relevanta KPI:er för logistikprestanda, samt deras inbördes relationer och påverkan. Forskningen tillämpar metoden ISM (Interpretive Structural Modeling) för att utveckla en hierarkisk modell av KPI:erna och deras orsakssamband. Den tolkande strukturella modellen av indikatorerna visar att de nuvarande indikatorerna som vanligtvis används i mejeriindustrin idag inte är lämpliga för att mäta prestanda, indikatorerna påverkar inte den nuvarande prestationen avsevärt utan återspeglar snarare resultaten. I denna rapport föreslås en metod för att utvärdera prestationsmått på ett kvalitativt sätt, baserat på integrationen av ISM-metoden, MICMAC-analysen och de sju kriterierna för en KPI. ISM-metoden är en teknik för att identifiera och analysera de inbördes relationerna mellan olika delar i ett komplext system. Genom att tillämpa denna metod kan organisationer och akademiker utvärdera lämpligheten och vikten av en uppsättning eller en KPI.