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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
271

Discrete Event Simulation of Cabinet Assembly at ABB Robotics and Discrete Automation

Allamkota Vijayaprasad, Venkhat Abhishek January 2021 (has links)
Planning of the optimised production system is an intricate task. The reason behind this is changing demand, variations, and other disturbances. The main purpose of this study the current performance in the existing production system and provide recommendations for optimising the production in order to accommodate a new product. Since, the addition of new products may lead to bottlenecks in the flow which affects the output performance. The bottlenecks would lead to ineffective results, while tying up the capital in the production downstream as inventory gets stagnated in the assembly lines. The performance evaluation is a tedious process however, the study probes into the use of flow simulation tool to analyse the production performance. In this thesis work, Discrete Event Simulation (DES) is utilised as a tool to examine the performance of the production systems and to determine the cost consuming areas. To achieve that, the production system is replicated as a functional model into the DES system with the appropriate logics and parameters, with the thorough understanding of the existing workflows. To supplement it, the data from the orders, resources, and parts are charted.In the later part, production flow is analysed with the additions of determined improvisations to understand the impact on the output. Later, investigations are performed to identify the challenges and applicable changes required to meet future output. As an outcome, the production system is restructured and optimised, thus getting an overview of the future production set up as a digital factory layout. / Planering av det optimerade produktionssystemet är en invecklad uppgift. Orsaken bakom detta är förändrad efterfrågan, variationer och andra störningar. Huvudsyftet med denna studie är den nuvarande prestandan i det befintliga produktionssystemet och ger rekommendationer för att optimera produktionen för att rymma en ny produkt. Eftersom tillägg av nya produkter kan leda till flaskhalsar i flödet som påverkar uteffekten. Flaskhalsarna skulle leda till ineffektiva resultat, samtidigt som kapitalet i produktionen binds nedströms när lagret stagnerar i löpande band. Prestationsutvärderingen är en tråkig process, men studien undersöker användningen av flödessimuleringsverktyg för att analysera produktionsprestanda. I detta avhandlingsarbete används Discrete Event Simulation (DES) som ett verktyg för att undersöka produktionssystemens prestanda och bestämma de kostnadskrävande områdena. För att uppnå det replikeras produktionssystemet som en funktionell modell i DES -systemet med lämpliga logiker och parametrar, med en grundlig förståelse av de befintliga arbetsflödena. För att komplettera det kartläggs data från order, resurser och delar. I den senare delen analyseras produktionsflödet med tillägg av bestämda improvisationer för att förstå effekten på produktionen. Senare utförs undersökningar för att identifiera de utmaningar och tillämpliga förändringar som krävs för att möta framtida produktion. Som ett resultat omstruktureras och optimeras produktionssystemet och får därmed en överblick över den framtida produktionsuppsättningen som en digital fabrikslayout.
272

All for the Greater Good: A Strategic, Tactical, and Operational Level Analysis of Supply Chain Goal and Incentive Alignment

McConville, Sean Cask 07 1900 (has links)
Goal and incentive alignment are a means of establishing collaborative behavior in supply chains. Essay 1 examines goal and incentive alignment at the strategic level in the purchasing process. It employs survey research in conjunction with structural equation modelling to examine the source selection strategy as a means of aligning the goals of the offeror with those of the buyer. Essay 2 examines goal and incentive alignment at the tactical level. It uses discrete event simulation to explore how the pursuit of localized profit objectives affects the global profitability of a supply chain. Lastly, Essay 3 examines goal and incentive alignment at the operational level. By employing a hybrid simulation approach to model a complex product refurbishment process, this research demonstrates that evaluating subprocesses based solely on their throughput does not equate to greater cost savings for the company at the focal point of this case study. These essays contribute to the body of knowledge in several ways. To the best of the author's knowledge, Essay 1 demonstrates the first empirical linkage, in the realm of public procurement, between the fear of a bid protest and the appropriateness of the sourcing strategy. Similarly, Essay 2 represents the first adaptation of Sterman's Beer Game to a format in which the value of products increases while they travel downstream. It also stands as the first research to quantitively explore the value of supply chain cooperation as a function of relative position in a supply chain. Lastly, the methodology employed in Essay 3 answers calls for research as they pertain to the need for case studies from industry, as well as the need to preserve the ‘real-world' context in complex, industry-based problems.
273

The COMPASS Paradigm For The Systematic Evaluation Of U.S. Army Command And Control Systems Using Neural Network And Discrete Event Computer Simulation

Middlebrooks, Sam E. 15 April 2003 (has links)
In today's technology based society the rapid proliferation of new machines and systems that would have been undreamed of only a few short years ago has become a way of life. Developments and advances especially in the areas of digital electronics and micro-circuitry have spawned subsequent technology based improvements in transportation, communications, entertainment, automation, the armed forces, and many other areas that would not have been possible otherwise. This rapid "explosion" of new capabilities and ways of performing tasks has been motivated as often as not by the philosophy that if it is possible to make something better or work faster or be more cost effective or operate over greater distances then it must inherently be good for the human operator. Taken further, these improvements typically are envisioned to consequently produce a more efficient operating system where the human operator is an integral component. The formal concept of human-system interface design has only emerged this century as a recognized academic discipline, however, the practice of developing ideas and concepts for systems containing human operators has been in existence since humans started experiencing cognitive thought. An example of a human system interface technology for communication and dissemination of written information that has evolved over centuries of trial and error development, is the book. It is no accident that the form and shape of the book of today is as it is. This is because it is a shape and form readily usable by human physiology whose optimal configuration was determined by centuries of effort and revision. This slow evolution was mirrored by a rate of technical evolution in printing and elsewhere that allowed new advances to be experimented with as part of the overall use requirement and need for the existence of the printed word and some way to contain it. Today, however, technology is advancing at such a rapid rate that evolutionary use requirements have no chance to develop along side the fast pace of technical progress. One result of this recognition is the establishment of disciplines like human factors engineering that have stated purposes and goals of systematic determination of good and bad human system interface designs. However, other results of this phenomenon are systems that get developed and placed into public use simply because new technology allowed them to be made. This development can proceed without a full appreciation of how the system might be used and, perhaps even more significantly, what impact the use of this new system might have on the operator within it. The U.S. Army has a term for this type of activity. It is called "stove-piped development". The implication of this term is that a system gets developed in isolation where the developers are only looking "up" and not "around". They are thus concerned only with how this system may work or be used for its own singular purposes as opposed to how it might be used in the larger community of existing systems and interfaces or, even more importantly, in the larger community of other new systems in concurrent development. Some of the impacts for the Army from this mode of system development are communication systems that work exactly as designed but are unable to interface to other communications systems in other domains for battlefield wide communications capabilities. Having communications systems that cannot communicate with each other is a distinct problem in its own right. However, when developments in one industry produce products that humans use or attempt to use with products from totally separate developments or industries, the Army concept of product development resulting from stove-piped design visions can have significant implication on the operation of each system and the human operator attempting to use it. There are many examples that would illustrate the above concept, however, one that will be explored here is the Army effort to study, understand, and optimize its command and control (C2) operations. This effort is at the heart of a change in the operational paradigm in C2 Tactical Operations Centers (TOCs) that the Army is now undergoing. For the 50 years since World War II the nature, organization, and mode of the operation of command organizations within the Army has remained virtually unchanged. Staffs have been organized on a basic four section structure and TOCs generally only operate in a totally static mode with the amount of time required to move them to keep up with a mobile battlefield going up almost exponentially from lower to higher command levels. However, current initiatives are changing all that and while new vehicles and hardware systems address individual components of the command structures to improve their operations, these initiatives do not necessarily provide the environment in which the human operator component of the overall system can function in a more effective manner. This dissertation examines C2 from a system level viewpoint using a new paradigm for systematically examining the way TOCs operate and then translating those observations into validated computer simulations using a methodological framework. This paradigm is called COmputer Modeling Paradigm And Simulation of Systems (COMPASS). COMPASS provides the ability to model TOC operations in a way that not only includes the individuals, work groups and teams in it, but also all of the other hardware and software systems and subsystems and human-system interfaces that comprise it as well as the facilities and environmental conditions that surround it. Most of the current literature and research in this area focuses on the concept of C2 itself and its follow-on activities of command, control, communications (C3), command, control, communications, and computers (C4), and command, control, communications, computers and intelligence (C4I). This focus tends to address the activities involved with the human processes within the overall system such as individual and team performance and the commander's decision-making process. While the literature acknowledges the existence of the command and control system (C2S), little effort has been expended to quantify and analyze C2Ss from a systemic viewpoint. A C2S is defined as the facilities, equipment, communications, procedures, and personnel necessary to support the commander (i.e., the primary decision maker within the system) for conducting the activities of planning, directing, and controlling the battlefield within the sector of operations applicable to the system. The research in this dissertation is in two phases. The overall project incorporates sequential experimentation procedures that build on successive TOC observation events to generate an evolving data store that supports the two phases of the project. Phase I consists of the observation of heavy maneuver battalion and brigade TOCs during peacetime exercises. The term "heavy maneuver" is used to connotate main battle forces such as armored and mechanized infantry units supported by artillery, air defense, close air, engineer, and other so called combat support elements. This type of unit comprises the main battle forces on the battlefield. It is used to refer to what is called the conventional force structure. These observations are conducted using naturalistic observation techniques of the visible functioning of activities within the TOC and are augmented by automatic data collection of such things as analog and digital message traffic, combat reports generated by the computer simulations supporting the wargame exercise, and video and audio recordings where appropriate and available. Visible activities within the TOC include primarily the human operator functions such as message handling activities, decision-making processes and timing, coordination activities, and span of control over the battlefield. They also include environmental conditions, functional status of computer and communications systems, and levels of message traffic flows. These observations are further augmented by observer estimations of such indicators as perceived level of stress, excitement, and level of attention to the mission of the TOC personnel. In other words, every visible and available component of the C2S within the TOC is recorded for analysis. No a priori attempt is made to evaluate the potential significance of each of the activities as their contribution may be so subtle as to only be ascertainable through statistical analysis. Each of these performance activities becomes an independent variable (IV) within the data that is compared against dependent variables (DV) identified according to the mission functions of the TOC. The DVs for the C2S are performance measures that are critical combat tasks performed by the system. Examples of critical combat tasks are "attacking to seize an objective", "seizure of key terrain", and "river crossings'. A list of expected critical combat tasks has been prepared from the literature and subject matter expert (SME) input. After the exercise is over, the success of these critical tasks attempted by the C2S during the wargame are established through evaluator assessments, if available, and/or TOC staff self analysis and reporting as presented during after action reviews. The second part of Phase I includes datamining procedures, including neural networks, used in a constrained format to analyze the data. The term constrained means that the identification of the outputs/DV is known. The process was to identify those IV that significantly contribute to the constrained DV. A neural network is then constructed where each IV forms an input node and each DV forms an output node. One layer of hidden nodes is used to complete the network. The number of hidden nodes and layers is determined through iterative analysis of the network. The completed network is then trained to replicate the output conditions through iterative epoch executions. The network is then pruned to remove input nodes that do not contribute significantly to the output condition. Once the neural network tree is pruned through iterative executions of the neural network, the resulting branches are used to develop algorithmic descriptors of the system in the form of regression like expressions. For Phase II these algorithmic expressions are incorporated into the CoHOST discrete event computer simulation model of the C2S. The programming environment is the commercial programming language Micro Saintä running on a PC microcomputer. An interrogation approach was developed to query these algorithms within the computer simulation to determine if they allow the simulation to reflect the activities observed in the real TOC to within an acceptable degree of accuracy. The purpose of this dissertation is to introduce the COMPASS concept that is a paradigm for developing techniques and procedures to translate as much of the performance of the entire TOC system as possible to an existing computer simulation that would be suitable for analyses of future system configurations. The approach consists of the following steps: • Naturalistic observation of the real system using ethnographic techniques. • Data analysis using datamining techniques such as neural networks. • Development of mathematical models of TOC performance activities. • Integration of the mathematical into the CoHOST computer simulation. • Interrogation of the computer simulation. • Assessment of the level of accuracy of the computer simulation. • Validation of the process as a viable system simulation approach. / Ph. D.
274

Simulation of circular material flows at the construction site / Simulering av cirkulära materialflöden på byggarbetsplatsen

Lundin, Julia January 2024 (has links)
The construction industry is the second largest producer of waste in Sweden, generating 14.2 million tons in 2020. The traditional linear economy in the construction industry contributes to significant waste generation and resource inefficiency. Effective material and waste management are critical to reducing this waste and meeting increased sustainability requirements from international and national organizations. Therefore, aims this study, as part of the larger project BÖRjA, to investigate and evaluate various strategies for waste management at construction sites through simulation models. The BÖRjA project, funded by Vinnova, aims to promote circular material flows and improve resource efficiency and transport efficiency in the construction industry. This study focuses on simulating waste flows at a construction site to evaluate and improve waste management strategies. By developing multiple simulation models, the study aims to assess the effect of different waste management methods on overall site efficiency, specifically by examining the use of elevators for waste transport, space utilization, fill levels, and container pickups. To address the aim, two research questions have been posed: How do different strategies for container and waste management impact workflow at the construction site? How does the pickup frequency of trucks affect the efficiency of waste management? The method used in the study is discrete event simulation, where a simplified construction site has been modeled. The model enables experimentation without disrupting actual site operations, offering a cost-effective and efficient way to gather insights. The model is based on one of NCC's construction projects, named Silverskatten, which includes two apartment buildings with a total of 77 units. Data for the models have been collected through observation, interviews, and collaborations with NCC and Ragn-Sells. The strategies tested in the simulation environment include a baseline scenario, representing the most common method based on interviews and observations, where bins are emptied when assumed to be full and containers are picked up by waste handlers based on demand. From the baseline scenario, two different strategies have been tested where a single resource is responsible for waste management. The final strategy tested includes scheduled waste pickups instead of pickups based on demand. A fill requirement has also been applied in the different strategies, specifying at what fill level bins and containers are allowed to be emptied. The results of the study showed that the use of elevators for waste transport indicated that at a fill requirement of 30%, the total elevator usage time was significantly higher compared to the baseline scenario and scenarios with 50 or 70% fill requirements. When dedicated workers were used, it affected the total elevator usage time for the following fill requirements of 30, 50, and 70% by +68, +14, and -10%, respectively. The study found that scheduling waste pickups can reduce the total number of pickups required. A fill requirement of 50% with scheduled pickups on Fridays resulted in the fewest pickups over 140 weeks, demonstrating the effectiveness of strategic scheduling. The total work time required for dedicated workers handling waste varied significantly with the fill level and elevator speed. At a fill requirement of 30% and an elevator speed of 15 m/min, the total work time was approximately 309.9 hours over 140 weeks, while at a fill requirement of 70% and an elevator speed of 25 m/min, it decreased to approximately 158.3 hours. Implementing dedicated workers for waste management reduced the maximum number of bins on each floor, freeing up valuable space at construction sites. / Byggindustrin är den näst största producenten av avfall i Sverige, med 14,2 miljoner ton genererat under 2020. Den traditionella linjära ekonomin i byggindustrin bidrar till betydande avfallsmängder och resursslöseri. Effektiv material- och avfallshantering är kritisk för att minska detta slöseri och uppfylla ökade hållbarhetskrav från internationella och nationella organ. Därför syftar denna studie, som är en del av det större projektet BÖRjA till att undersöka och utvärdera olika strategier för avfallshantering på byggarbetsplatser genom simuleringsmodeller. Projektet BÖRjA, finansierat av Vinnova, strävar efter att främja cirkulära materialflöden och förbättra resurseffektiviteten och transporteffektiviteten i byggindustrin. Denna studie fokuserar på att simulera avfallsflöden på en byggarbetsplats för att utvärdera och förbättra avfallshanteringsstrategier. Genom att utveckla flera simuleringsmodeller syftar studien till att bedöma effekten av olika avfallshanteringsmetoder på den övergripande arbetsplatseffektiviteten, specifikt genom att undersöka användningen av hissar för avfallstransport, utrymmesanvändning och fyllnadsgrader samt upphämtningar av lastbärare. För att besvara syftet har två frågeställningar använts: Hur påverkar olika strategier för hantering av lastbärare och avfall arbetsflödet på byggarbetsplatsen? Hur påverkar upphämtningsfrekvensen för lastbilar avfallshanteringens effektivitet? Metoden som använts i studien är diskret händelsestyrd simulering där en förenklad byggarbetsplats modellerats. Modellen möjliggör experiment utan att störa faktiska arbetsplatsoperationer, vilket erbjuder ett kostnadseffektivt och effektivt sätt att samla insikter. Modellen bygger på ett av NCCs byggprojekt, kallat Silverskatten, vilket inkluderar två lägenhetshus med totalt 77 lägenheter. Data för modellerna har samlats in via observation, intervjuer och samarbeten med NCC och Ragn-Sells. De strategier som testats i simuleringsmiljön innefattar ett grundscenario, vilket ska representera den vanligaste metoden utifrån intervjuer och observationer, där kärl töms när de antas vara fulla och lastbärare upphämtas av avfallshanterare utifrån behov. Utifrån grundscenariot har sedan två olika strategier testats där en ensam resurs ansvarar över avfallshanteringen. Den sista strategin som testats innefattar schemalagd upphämtning av avfall istället för upphämtning utifrån behov. Ett fyllnadskrav har även applicerats i de olika strategierna där fyllnadskravet specificerar vid vilken fyllnadsgrad som kärl och lastbärare får tömmas. Resultatet av studien visade att användningen av hissar för avfallstransport visade att vid ett fyllnadskrav på 30% var den totala hissanvändningstiden avsevärt högre jämfört med grundscenariot och scenarier med 50 eller 70% som fyllnadskrav. När dedikerad arbetare användes påverkade det hissens totala användningstid för följande fyllnadskrav 30, 50 och 70% med +68, +14 och -10%. Studien fann att schemaläggning av avfallshämtningar kan minska det totala antalet hämtningar som krävs. Ett fyllnadskrav på 50% med schemalagda upphämtningar på fredagar resulterade i det minsta antalet hämtningar över 140 veckor, vilket visar effektiviteten av strategisk schemaläggning. Den totala arbetstiden som krävdes för dedikerade arbetare som hanterar avfall varierade avsevärt med fyllnadsgraden och hissen hastighet. Vid ett fyllnadskrav på 30% och en hisshastighet på 15 m/min var den totala arbetstiden cirka 309,9 timmar över 140 veckor, medan vid en fyllnadskrav på 70% och en hisshastighet på 25 m/min minskade den till cirka 158,3 timmar. Implementering av dedikerad arbetare för avfallshantering minskade det maximala antalet kärl på varje våning, vilket frigjorde värdefullt utrymme på byggarbetsplatser.
275

Redesigning the Barranquilla's public emergency care network to improve the patient waiting time

Ortíz Barrios, Miguel Ángel 27 November 2020 (has links)
Tesis por compendio / [ES] La oportunidad en la atención es uno de los críticos de mayor relevancia en la satisfacción de los pacientes que acuden a los servicios de Urgencias. Por tal motivo, las instituciones prestadoras de servicio y las organizaciones gubernamentales deben propender conjuntamente por una atención cada vez más oportuna a costos operacionales razonables. En el caso de la Red Pública en Servicios de Urgencias de Barrannquilla, compuesta por 8 puntos de atención y 2 hospitales, la tendencia marca un continuo crecimiento de la oportunidad en la atención con una tasa de 3,08 minutos/semestre y una probabilidad del 93,13% de atender a los pacientes después de una espera mayor a 30 minutos. Lo anterior se constituye en un síntoma inequívoco de la incapacidad de la Red para satisfacer los estándares de oportunidad establecidos por el Ministerio de Salud, hecho que podría desencadenar el desarrollo de sintomatologías de mayor complejidad, el incremento de la probabilidad de mortalidad, el requerimiento de servicios clínicos más complejos (hospitalización y cuidados intensivos) y el aumento de los costos asociados al servicio. En consecuencia, la presente tesis doctoral presenta el rediseño de la Red Pública en Servicios de Urgencias anteriormente mencionada a fin de otorgar a la población diana un servicio eficiente y altamente oportuno donde tanto las instituciones prestadoras del servicio como los organismos gubernamentales converjan efectivamente. Para ello, fue necesaria la ejecución de 4 grandes fases a través de las cuales se consolidó una propuesta orientada al desarrollo efectivo y sostenible de las operaciones de la Red. Primero, se caracterizó la Red Pública de Servicios de Urgencias en Salud considerando su comportamiento actual en términos de demanda y oportunidad de la atención. Luego, a través de una revisión sistemática de la literatura, se identificaron los enfoques metodológicos que se han implementado para la mejora de la oportunidad y otros indicadores de rendimiento asociados al servicio de Urgencias. Posteriormente, se diseñó una metodología para la creación de redes de Urgencias eficientes y sostenibles la cual luego se validó en la Red Pública sudamericana a fin de disminuir la oportunidad de atención promedio en Urgencias y garantizar la distribución equitativa de los beneficios financieros derivados de la colaboración. Finalmente, se construyó un modelo multicriterio que permitió evaluar el rendimiento de los departamentos de Urgencia e impulsó la creación de estrategias de mejora focalizadas en incrementar su respuesta ante la demanda cambiante, los críticos de satisfacción y las condiciones de operación estipuladas en la ley. Los resultados de esta aplicación evidenciaron que los pacientes que acceden a la Red tienden a esperar en promedio 201,6 min con desviación de estándar de 81,6 min antes de ser atendidos por urgencia. Por otro lado, de acuerdo con la revisión de literatura, la combinación de técnicas de investigación de operaciones, ingeniería de la calidad y analítica de datos es ampliamente recomendada para abordar este problema. En ese sentido, una metodología basada en modelos colaterales de pago, simulación de procesos y lean seis sigma fue propuesta y validada generando un rediseño de Red cuya oportunidad de atención promedio podría disminuir entre 6,71 min y 9,08 min con beneficios financieros promedio de US$29,980/nodo. En último lugar, un modelo compuesto por 8 criterios y 35 sub-criterios fue diseñado para evaluar el rendimiento general de los departamentos de Urgencias. Los resultados del modelo evidenciaron el rol crítico de la infraestructura (Peso global = 21,5%) en el rendimiento de los departamentos de Urgencia y la naturaleza interactiva de la Seguridad del Paciente (C + R = 12,771). / [CA] L'oportunitat en l'atenció és un dels crítics de major rellevància en la satisfacció dels pacients que acudeixen als serveis d'Urgències. Per tal motiu, les institucions prestadores de servei i les organitzacions governamentals han de propendir conjuntament per una atenció cada vegada més oportuna a costos operacionals raonables. En el cas de la Xarxa Pública en Serveis d'Urgències de Barrannquilla, composta per 8 punts d'atenció i 2 hospitals, la tendència marca un continu creixement de l'oportunitat en l'atenció amb una taxa de 3,08 minuts / semestre i una probabilitat de l' 93,13% d'atendre els pacients després d'una espera major a 30 minuts. L'anterior es constitueix en un símptoma inequívoc de la incapacitat de la Xarxa per satisfer els estàndards d'oportunitat establerts pel Ministeri de Salut, fet que podria desencadenar el desenvolupament de simptomatologies de major complexitat, l'increment de la probabilitat de mortalitat, el requeriment de serveis clínics més complexos (hospitalització i cures intensives) i l'augment dels costos associats a el servei. En conseqüència, la present tesi doctoral presenta el redisseny de la Xarxa Pública en Serveis d'Urgències anteriorment esmentada a fi d'atorgar a la població diana un servei eficient i altament oportú on tant les institucions prestadores de el servei com els organismes governamentals convergeixin efectivament. Per a això, va ser necessària l'execució de 4 grans fases a través de les quals es va consolidar una proposta orientada a el desenvolupament efectiu i sostenible de les operacions de la Xarxa. Primer, es va caracteritzar la Xarxa Pública de Serveis d'Urgències en Salut considerant el seu comportament actual en termes de demanda i oportunitat de l'atenció. Després, a través d'una revisió sistemàtica de la literatura, es van identificar els enfocaments metodològics que s'han implementat per a la millora de l'oportunitat i altres indicadors de rendiment associats a el servei d'Urgències. Posteriorment, es va dissenyar una metodologia per a la creació de xarxes d'Urgències eficients i sostenibles la qual després es va validar a la Xarxa Pública sud-americana a fi de disminuir l'oportunitat d'atenció mitjana a Urgències i garantir la distribució equitativa dels beneficis financers derivats de la col´laboració. Finalment, es va construir un model multicriteri que va permetre avaluar el rendiment dels departaments d'Urgència i va impulsar la creació d'estratègies de millora focalitzades en incrementar la seva resposta davant la demanda canviant, els crítics de satisfacció i les condicions d'operació estipulades en la llei. Els resultats d'aquesta aplicació van evidenciar que els pacients que accedeixen a la Xarxa tendeixen a esperar de mitjana 201,6 min amb desviació d'estàndard de 81,6 min abans de ser atesos per urgència. D'altra banda, d'acord amb la revisió de literatura, la combinació de tècniques d'investigació d'operacions, enginyeria de la qualitat i analítica de dades és àmpliament recomanada per abordar aquest problema. En aquest sentit, una metodologia basada en models col´laterals de pagament, simulació de processos i llegeixin 6 sigma va ser proposada i validada generant un redisseny de Xarxa la oportunitat d'atenció mitjana podria disminuir entre 6,71 min i 9,08 min amb beneficis financers mitjana d'US $ 29,980 / node. En darrer lloc, un model compost per 8 criteris i 35 sub-criteris va ser dissenyat per avaluar el rendiment general dels departaments d'Urgències. Els resultats de el model evidenciar el paper crític de la infraestructura (Pes global = 21,5%) en el rendiment dels departaments d'Urgència i la naturalesa interactiva de la Seguretat de l'Pacient (C + R = 12,771). / [EN] Waiting time is one of the most critical measures in the satisfaction of patients admitted within emergency departments. Therefore, hospitals and governmental organizations should jointly aim to provide timely attention at reasonable costs. In the case of Barranquilla's Pubic Emergency Service Network, composed by 8 Points of care (POCs) and 2 hospitals, the trend evidences a continuous growing of the waiting time with a rate of 3,08 min/semester and a 93,13% likelihood of serving patients after waiting for more than 30 minutes. This is an unmistakable symptom of the network inability for satisfying the standards established by the Ministry of Health, which may trigger the development of more complex symptoms, increase in the death rate, requirement for more complex clinical services (hospitalization and intensive care unit) and increased service costs. This doctoral dissertation then illustrates the redesign of the aforementioned Public Emergency Service Network aiming at providing the target population with an efficient and highly timely service where both hospitals and governmental institutions effectively converge. It was then necessary to implement a 4-phase methodology consolidating a proposal oriented to the effective and sustainable development of network operations. First, the Public Emergency Service Network was characterized considering its current behavior in terms of demand and waiting time. A systematic literature review was then undertaken for identifying the methodological approaches that have been implementing for improving the waiting time and other performance indicators associated with the emergency care service. Following this, a methodology for the creation of efficient and sustainable emergency care networks was designed and later validated in the Southamerican Public network for lessening the average waiting time and ensuring the equitable distribution of profits derived from the collaboration. Ultimately, a multicriteria decision-making model was created for assessing the performance of the emergency departments and propelling the design of improvement strategies focused on bettering the response against the changing demand conditions, critical to satisfaction and operational conditions. The results evidenced that the patients accessing to the network tend to wait 201,6 min on average with a standard deviation of 81,6 min before being served by the emergency care unit. On the other hand, based on the reported literature, it is highly suggested to combine Operations Research (OR) methods, quality-based techniques, and data-driven approaches for addressing this problem. In this sense, a methodology based on collateral payment models, Discrete-event simulation, and Lean Six Sigma was proposed and validated resulting in a redesigned network whose average waiting time may diminish between 6,71 min and 9,08 min with an average profit US$29,980/node. Lately, a model comprising of 8 criteria and 35 sub-criteria was designed for evaluating the overall performance of emergency departments. The model outcomes revealed the critical role of Infrastructure (Global weight = 21,5%) in ED performance and the interactive nature of Patient Safety (C + R = 12,771). / Ortíz Barrios, MÁ. (2020). Redesigning the Barranquilla's public emergency care network to improve the patient waiting time [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/156215 / Compendio
276

The SBLPO framework: A practical framework for performing simulation-based optimization integrated facility layout studies : A case study at Sandvik Mining and Rock Solutions manufacturing facility in Alachua, Florida

Lannerås, Jonathan, Darner, Tobias January 2024 (has links)
This master thesis presents a practical framework for integrating Simulation-Based Optimization into facility layout studies. While various methodologies exist for improving facility layouts and the utilization of Simulation-based Optimization, there is a gap in practical frameworks offering a systematic approach to combine these methods effectively. Existing frameworks lack specificity, require substantial prior knowledge, and offer limited insight into the methodologies employed. Consequently, there is a need for a comprehensive, step-by-step framework accessible to a broader range of practitioners. The proposed framework addresses this gap by providing a practical step-by-step approach that guides practitioners through a Simulation-Based Optimization integrated facility layout study. This framework facilitates the development of alternative layouts and system configurations using trusted methods. To assess the proposed framework, a case study was conducted at a manufacturing facility with the purpose of enhancing the production throughput. The case study followed the steps outlined in the framework in a real-world scenario, which provided valuable insights into the practicality and usefulness of the framework. The framework's effectiveness hinges on careful execution of each step, particularly given its front-loaded nature. Neglecting any step could lead to inaccuracies in subsequent stages, undermining the overall validity of the study. Adequate time allocation, especially in data collection and simulation model development, is critical to ensuring robust results. While the framework's applicability has been demonstrated in a high-mix low-volume production environment, its broader effectiveness across different settings remains to be explored. Nonetheless, the framework's intuitive flow and reliance on established methodologies enhance its usability and potential to improve production system throughput. Ultimately, the study contributes a tangible solution to the research question, offering practitioners a valuable tool for streamlining production.
277

Optimering av lagerprocesser i läkemedelsindustrin med diskret event simulering och prognostisering / Optimization of warehouse processes in the pharmaceutical industry with discrete event simulation and forecasting

Hartz, Alexander, Markroth, Arvid January 2024 (has links)
Denna studie undersöker hur utgående logistik inom läkemedelsindustrin kan förbättras med hjälp av diskret event simulering (DES) och prognostisering. Komplexa logistiksystem och stora variationer kännetecknar outbound-logistik inom denna bransch, vilket leder till utmaningar som kapitalbindning, kapacitetsbegränsningar och begränsad lageryta. Simuleringar användes för att identifiera flaskhalsar och utvärdera förbättringsförslag. Att kombinera DES med prognostisering möjliggjorde analys av framtida utgående volymer. En simuleringsmodell utvecklades för att representera logistiksystemet, med hänsyn till faktorer som tillgängliga resurser och ledtider. Studien visade att det nuvarande systemet inte kunde hantera den prognostiserade ökningen av efterfrågan på den europeiska marknaden utan modifieringar. Modellen verifierades och validerades med hjälp av verklig data som sedan användes för att utvärdera tre förbättringsförslag: att lägga till en extra etiketteringsmaskin, öka antalet lagringsplatser för Europapallar och förlänga slottiderna för lastbilshämtningar. Resultatet visade att det skulle vara nödvändigt att implementera alla tre förslagen för att möta den prognostiserade efterfrågan. Denna strategi kan hjälpa läkemedelsföretag att identifiera och hantera potentiella problem i sin utgående logistik, vilket säkerställer effektiva och punktliga leveranser. / This study investigates how outbound logistics can be improved in the pharmaceutical industry using discrete event simulation (DES) and forecasting. Complex logistic systems and high variation characterize outbound logistics in this industry, leading to challenges like capital tie-ups, capacity constraints, and limited warehouse space. Simulations were used to identify bottlenecks and evaluate improvement proposals. Combining DES with forecasting allowed for the analysis of future outbound volumes. A simulation model was developed to represent the outbound logistics system, considering factors like available resources and lead times. The study found that the current outbound logistics system cannot handle the forecasted increase in demand for the European market without modification. The model was verified and validated using real-world data to evaluate three improvement proposals: adding an additional labeling machine, increasing the number of storage bays for Europe-bound pallets, and adding slot times for truck pickups. The results showed that implementing all three proposals would be necessary to meet the projected demand. This approach can help pharmaceutical companies identify and address potential issues in their outbound logistics, ensuring efficient and timely deliveries.
278

Modelling the shift in the balance of care in the NHS

Marshall, Carol January 2013 (has links)
The concept of Shifting the Balance of Care was first introduced to NHS Scotland in 2005 through the Kerr Report. The key messages from the report were to: ensure sustainable and safe local services, which are supported by the right skills, change the emphasis of care into the community, provide preventative reactive care, and fully integrate the system to tackle the changes, use technology more effectively, and involve the public in finding solutions to change. Following the report, a framework was developed which highlighted and prioritised eight areas of improvement. These areas for improvement are the focus by which this research examines if Operational Research (OR), specifically OR models, can have a positive impact in Shifting the Balance of Care. The research utilises underlying OR methodologies and methods and provides evidence from the literature of the ability of nine selected models to facilitate the Shift in the Balance of Care. A contributing factor to the research is the barriers to implementation of OR models into the NHS. With reference to the literature, the common barriers to implementation of OR models are categorised and used to provide direction to modellers where implementation barriers are more prevalent in some models than in others. The research also provides empirical evidence of three selected models’ (the Lean Methodology, Process Mapping and Simulation, developed over two Case Studies) ability to address and influence the prioritised Improvement Areas, with the addition of a newly developed model: SoApt. The development of SoApt follows the Principles of Model Development derived as a guide to modellers who wish to develop a new model. SoApt is also empirically explored in a Case Study and provides some evidence of the models ability to aid Decision-makers, faced with limited budgets, to choose between options which will Shift the Balance of Care. OR methods and methodologies are examined to ascertain the Roles of Models for each model explored in the Case Studies. Examination of the Roles of Models against the Improvement Areas provided evidence of a models’ ability to address more than one of the priority areas and that models can be used together or sequentially. In addition, with reference to OR methods and methodologies, a theoretical Evaluation Framework is proposed which suggests the User and User Satisfaction is key to the evaluation of a model’s success; positive experiences of the User and Use of the model may help to eliminate some of the barriers to implementation.
279

Unapređenje efikasnosti proizvodnih procesa razvojem proširenog modela toka vrednosti / Improving manufacturing efficiency by developing expanded value stream model

Gračanin Danijela 24 October 2014 (has links)
<p>U okviru disertacije se ispituje uticaj akumulacije troškova u vremenu na izbor odgovarajućih mera za unapređenje i povećanje efikasnosti proizvodnih procesa. Ovaj uticaj je stavljen u kontekst lin proizvodnje i procesa mapiranja toka vrednosti, ali je ispitivan i uticaj izbora pravila raspoređivanja radnih naloga, odnosno terminskog planiranja na vremensko-troškovno ulaganje. Kao rezultat istraživanja i originalan naučni doprinos ove disertacije predloženi su koeficijenti ulaganja i efikasnosti mera unapređenja koji se koriste, na prvom mestu za izbor odgovarajuće mere unapređenja, a zatim i za definisanje prioriteta sprovođenja mera.</p> / <p>This dissertation examines the impact of the cost accumulation over the time on the selection of appropriate measures to improve and increase the efficiency of production processes. This effect has been put into the context of lean production and value stream mapping, but there is also examines the impact of job shop schenduling on cost-time investment. As a result of research and original scientific contribution of this thesis two coefficients are proposed: coefficient of investment and coefficient of measure efficiency that can be used in the first place for the selection of appropriate measure for the improvement, and then to define the priorities for implementing the improvement measures.</p>
280

Economic evaluations of a pharmacogenomics test for Statin-induced myopathy in secondary cardiovascular prevention

Mitchell, Dominic 03 1900 (has links)
No description available.

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