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Lidman, Fredrik, and Johannes Sandgren. "Stadium central warehouse - possibilities to an improved picking process." Thesis, Linköpings universitet, Kommunikations- och transportsystem, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-141680.
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Stadium driver i dagsläget en centrallagerlösning i Norrköping sedan år 2006. Det har skett en stabil ökning av både butiker samt omsättning sedan bolaget startades. Stadium har ett avtal med PostNord angående driften av lagerverksamheten på centrallagret samt Pema angående bemanningen. Bolagets ökning av butiker har lett till att de nått en väldigt hög nivå i beläggning i centrallagret och därför behövdes en genomlysning av centrallagrets plockprocesser ske. Ett beslutsunderlag har tagits fram för att hjälpa Stadiumlagret med sin frekvensläggning av orderplocket. Två olika plockprocesser har jämförts med varandra, Banan och ett plocktorg. Banan är en automatiserad bana där plocklådor med ordrar transporteras längs Banans olika plockzoner, medan plocktorget är en tom yta där pallar med artiklar placeras och sedan plockas. Tidsstudier och observationer genomfördes på både Banan och plocktorget och dess olika steg i processerna, för att se vilken som var mest tidseffektiv. Kriterier och variabler togs fram för att kunna avgöra vad det är som påverkar respektive plockprocess. Beräkningar utformades för att göra Banans och plocktorgets tider jämförbara. Den plockprocess som sedan tog minst tid totalt skulle vara den bästa plockprocessen att plocka i. För att utforma ett beslutsunderlag som enkelt skulle illustrera ifall skor skulle plockas på plocktorget eller Banan, gjorde valet att utforma beslutsunderlaget i en matris. I matrisen illustreras vid vilket antal artiklar en brytpunkt finns där det skulle vara bättre att plocka på plocktorg. För att undersöka ifall centrallagret någon gång kom upp i de kvantiteter som krävdes för att nå brytpunkten användes verkliga exempel. En känslighetsanalys genomfördes där data från verkliga exempel användes och sorterades på olika sätt, för att undersöka om stora skillnader i resultatet i matrisen skulle uppenbaras. Det resulterade i sex olika matriser, tre olika sorteringar för två separata dagar av orderplock. Beslutsunderlagets matris visade att Banan var den mest effektiva plockprocessen att använda i den dagliga verksamheten för orderplocket. Anledningen till det var att Stadiumlagret inte plockade skor i de kvantiteter som brytpunkterna efterfrågade. Oavsett hur datan sorteras så övergick aldrig den totala kvantiteten av orderplock de brytpunkterna som hade beräknats. Det var en av sorteringarna som kom närmre brytpunkten än de andra två, men inte tillräckligt nära för att frekvenslägga orderplocket på plocktroget istället för Banan. Rekommendationen till PostNord blev därför att de inte skulle använda plocktorget till det ordinarie orderplocket i den dagliga verksamheten, på grund av att det är mindre effektivt att plocka på plocktorget. Plocktorget kan dock användas som ett komplement till Banan precis som den används i dagsläget. Tillfällen då plocktorget kan användas är när det exempelvis inte finns tillräckligt antal lediga plockplatser på Banan, om artiklarna är för otympliga för att plocka på Banan eller om antalet pieces av en artikel skulle medföra orimligt många påfyllningar av Banans plockplatser.
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Khachatryan, Margarit. "Small parts high volume order picking systems." Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-11192006-170829/.
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Thesis (Ph. D.)--Industrial and Systems Engineering, Georgia Institute of Technology, 2007.<br>Paul M. Griffin, Committee Member ; Gunter P. Sharp, Committee Member ; Hayriye Ayhan, Committee Member ; Leon F. McGinnis, Committee Chair ; Soumen Ghosh, Committee Member.
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JUNIOR, ANNIBAL THEOPHILO DA SILVA RODRIGUES. "A SIMULATION MODEL FOR PICKING UP INBOUND CONTAINERS WITH TIME WINDOWS IN A PORT TERMINAL." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2009. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=13448@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO<br>Nesta dissertação aborda-se um problema pouco estudado - o processo de
planejamento/programação de saída de contêineres de importação, movimentados
por reach stackers. Clientes pré-agendam a retirada de seus contêineres em
janelas de tempo de duas horas, sem especificação de horário. Efetua-se a présegregação
dos contêineres na noite anterior à da efetiva entrega, com a formação
de pilhas por faixa de horário e área buffer para a movimentação. A proposta deste
trabalho é identificar e avaliar comparativamente as variáveis de desempenho
envolvidas no atendimento de um máximo de 30 contêineres em cada janela de
tempo, estruturados em seis pilhas de cinco contêineres de altura cada. São
analisadas duas regras de sequenciamento diversas: (a) Primeiro a entrar, primeiro
a sair (PEPS) e (b) Tempo de processamento mínimo (SPT) ou Movimentação
Mínima (que se confundem neste problema). O modelo é necessariamente de
simulação, uma vez que o processo em estudo envolve a movimentação de pilhas
de contêineres (formadas aleatoriamente), com acesso por equipamentos stackers
(segundo políticas de acesso típicas), e chegada das carretas com ordenamento
aleatório, segundo distribuição própria. Com a aplicação do modelo, conclui-se
que, num regime de atendimento PEPS, a janela de tempo de duas horas é
insuficiente para atender à demanda de 30 (trinta) contêineres em um regime de
chegada segundo Poisson. Já no segundo regime de atendimento estudado, com
atendimento seletivo de fila de espera segundo critério decisório de movimentação
mínima esperada, os resultados foram bastantes mais promissores embora
insuficientes ao atendimento das carretas, em média, na janela de tempo
disponibilizada e nas condições operacionais oferecidas pela instalação. Cenários
outros foram simulados e seus resultados devidamente avaliados.<br>In this work, the focus is on a rarely studied problem in the technical
literature - the inbound containers (importation) process delivery, with reach
stackers for moving the containers . In this process, customers schedule their
containers withdrawal in one of the several allowable time windows - two hours
time, without fixed arrival order. Containers pre-segregation occurs in the night
before the effective delivery day. Thirty containers are stacked by time windows
in six stacks five containers high and a buffer area allocated for subsidiary
movements. The purpose of this work is to identify and to evaluate comparatively
the key performance indicators associated with the thirty containers maximum
delivery levels in each time window. The model is necessarily a simulation one,
because it involves the container stack packing (random), its access and
movement by reach stacker equipment (with typical access policies) and the truck
arrival for withdrawing the container (also random). Two different sequencing
rules are compared - first in, first out (FIFO) and smallest processing time (SPT).
Solving the model in a FIFO delivery discipline, the conclusion is that the two
hours time window is insufficient to deal with the 30 (thirty) containers delivery
in a Poisson process arriving trucks. The second delivery system studied - a
decision process applied in the waiting queue (based on selecting the container
with the minimal expected unproductive movements), more promising results
have been obtained, although insufficient to pick up all the containers. Alternative
scenarios were then offered to solve the problem.
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Desai, Sagar S. "For Whom the Time Stops: Picking Up the Pieces in a World of Constant Motion." University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1460731395.
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Boddu, Arathi. "A procedure to evaluate the costs and benefits of managing staffing levels in an order picking operation." Ohio : Ohio University, 2006. http://www.ohiolink.edu/etd/view.cgi?ohiou1155309515.
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Zeru, Berhane, and Ahmed Hamdi. "Artikeloptimering avseende plockfrekvens : Fallstudie om fast och flytande artikelplacering." Thesis, Högskolan i Gävle, Avdelningen för industriell ekonomi, industridesign och maskinteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-36985.
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Detta är en studie av artikelplaceringar på logistikföretaget som är placerade pålagerplatser som inte gynnar artiklarnas omsättning. Lagerplatser som är ogynnsamma avA-klassicerande artiklar har påverkat plockfrekvens negativt. Det har bidragit att ledtidenfrån att hämta en A- artikel tar längre tid än att hämta en annan A-artikel med lägreomsättning. Studien identifierar de negativa aspekter som påverkar plockfrekvens och vill bidra medförbättringsförslag för logistikföretaget. Studiens metod skapades genom att samla in datafrån både primär-och sekundärdata. Frågeställning var en del av strukturerad observationoch olika vetenskapliga artiklar relaterade till ämnesområdet samt litteratursökning varen del av primärdata. Studien har resulterat att orsakerna som är ABC-klassificering och Lean har en kopplingtill sambandet mellan artikelplacering och plocktid. Orsakerna som förekommer harbidragit negativ påverkan hos logistikföretaget. Vidare har studien kommit fram till ett resultat genom intervjuer och litteraturteorier därlogistikföretaget förlorar många produktionstimmar kring orsaken. Logistikföretagetbehöver implementera nya åtgärder för förbättring och utveckling. Slutsatsen iundersökningen redovisar vad logistikföretaget ska åtgärda de negativa aspekterna sompåverkar artikelplacering och plocktiden. • Minimera slöseri genom att förkorta gångavståndet. • Omsortera artiklarna. • Kompetensutveckling inom Lean och 5S för att jobba smartare. • Implementera olika standarden som hjälper till att förnya arbetssätt ochutveckling. • Upprätthålla ordning och reda genom att identifiera artiklar som behöverplaceras om och leverantörer. • Utöva mer av parametrar (försäljning, uttag och plockfrekvens). • Effektivisera lagerhanteringssystem (in-och utleveranser, plock, lagerplatser). Arbetet avgränsas till en del av artikeloptimering inom logistik och placering av Aklassificerade artiklar samt påverkan i plockfrekvensen. COVID-19 har varit understudiens tid ett hinder som begränsade studiens författare vistelse hos logistikföretaget.<br>The purpose of the survey is to investigate article placements at the logistics companythat are unproductively located. Unproductive places of A-classing articles have had anegative effect on picking frequency, which has contributed to the lead time to retrieveone A-article taking longer than retrieving another A-article with lower turnover. The purpose of the survey is to identify the negative aspects that affect the pickingfrequency in order to provide the logistics company with information about the aspectsthat indicate improvement. The method survey was created by collecting data throughboth primary and secondary data. Structured observation and questioning were part of a semi-structured interview andvarious scientific articles related to the subject area as well as literature search were partof secondary data. The investigation has resulted in the current reasons behind theconnection between article placement and picking time having been negatively affectedby the logistics company. Furthermore, research has come to a result where the logistics company loses manyproduction hours around the cause that need to implement new measures for improvementand development. The conclusion of the survey reports that the logistics company shouldaddress the negative aspects that affect item placement and picking time. • Minimize waste by shortening the walking distance. • Rearrange the items. • Skills development within Lean and 5S to work smarter. • Maintain order by identifying items that need to be repositioned and suppliers. • Exercise more parameters (sales, withdrawals and picking frequency). • Streamline inventory managementsystems (inbound and outbound deliveries,picks, warehouse locations). The work was limited to part of article optimization in logistics and placement of Aclassified articles and the impact on the picking frequency. During the study, COVID-19 has been an obstacle that limited the study's authors to stay longer with the logisticscompany.
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Vu, Thanh-Hai [Verfasser], and Jens Nobert [Akademischer Betreuer] Wünsche. "The effect of picking time and postharvest treatments on fruit quality of mango (Mangifera indica L.) / Vu Thanh Hai. Betreuer: Jens Nobert Wünsche." Hohenheim : Kommunikations-, Informations- und Medienzentrum der Universität Hohenheim, 2012. http://d-nb.info/102856712X/34.
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Kuang, Peiying, and Mahmood Ali. "E-Grocery in Digital Age : ICA MAXI in Gävle." Thesis, Högskolan i Gävle, Avdelningen för ekonomi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-17689.
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Aim: The purpose of this study is to identify factors that can attract customers to buy online and help the grocers to improve their online grocery services to retain and obtain customers. Design/Methodology/Approach: A qualitative method was used, based on triangulation methodology including observation and interviews of manager and employees. Quantitative data was collected by handing out questionnaire to 204 potential customers and 30 existing customers. Findings: The study shows that product and service quality, time saving and convenience, web page layout, customers’ trust in grocers (service providers), store image and advertising are the important factors that customers consider when they decide to use online grocer service. E- grocers also need to consider these factors when they start online grocery service. Suggestions for Future Research: An extensive study with large population sample and co- operation from other companies can help to generalize the results. Future studies can be extended to include drive-in and shared reception box service method, and consider the cost for the customers in e-grocery sector.
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Gilliland, Ellen. "An Assessment of Hypocenter Errors Associated with the Seismic Monitoring of Induced Hydro-fracturing in Hydrocarbon Reservoirs." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/45325.
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Expanding the standard, single-well recording geometry used to monitor seismicity during hydro-fracture treatments could provide more accurate hypocenter locations and seismic velocities, improving general reservoir characterization. However, for the real, two-well data set obtained for this project, only S-wave picks were available, and testing resulted in anomalous hypocenter location behavior. This study uses a hypocenter location algorithm and both real and synthetic data sets to investigate how the accuracy of the velocity model, starting hypocenter location, recording geometry, and arrival-time picking error affect final hypocenter locations.
Hypocenter locations improved using a velocity model that closely matched the observed sonic log rather than a smoothed version of this model. The starting hypocenter location did not affect the final location solution if both starting and final locations were between the wells. Two solutions were possible when the true solution was not directly between the wells. Adding realistic random picking errors to synthetic data closely modeled the dispersed hypocenter error pattern observed in the real data results. Adding data from a third well to synthetic tests dramatically reduced location error and removed horizontal geometric bias observed in the two-well case.
Seismic event data recorded during hydro-fracture treatments could potentially be used for three-dimensional joint hypocenter-velocity tomography. This would require observation wells close enough to earthquakes to record P- and S-wave arrivals or wells at orientations sufficient to properly triangulate hypocenter locations. Simulating results with synthetic tests before drilling could optimize survey design to collect data more effectively and make analysis more useful.<br>Master of Science
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Lidner, Beatrice, and Emilia Grenstadius. "Optimeringsmetod för färdigvarulager : En fallstudie hos Emballator Växjöplast." Thesis, Linnéuniversitetet, Institutionen för ekonomistyrning och logistik (ELO), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-76400.
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Uppsatsen undersöker hur Emballator Växjöplast prioriterar och resonerar kring aspekterna volymutnyttjande, plocktid, säkerhet, kapitalbindning och servicenivå vid optimering av deras färdigvarulager. Författarna kom fram till följande slutsats: Fallföretaget prioriterar säkerhet högst för att skydda individen Servicenivå prioriteras efter säkerhet då de arbetar kundfokuserat. Efter servicenivå prioriteras volymutnyttjande för att minska sin externlagring. Plocktid prioriteras efter volymutnyttjande där målsättningen är att undvika nyanställningar. Sist prioriteras kapitalbindning då denna inte är fokus för logistikfunktionen. Vidare undersöker författarna hur en multi-criteria optimization av aspekterna vid optimering av färdigvarulagret kan gå till. Författarna kommer fram till följande slutsatser: The main criteria method är bäst lämpad optimeringsmetod. Volymutnyttjande ska minimeras givet att resterande aspekter uppfyller respektive bivillkor. De flesta förvaringsmetoder och artikelplaceringar uppfyller aspekternas bivillkor Bäst lämpad förvaringsmetod och artikelplacering grundas därför på vilken som möjliggör bäst volymutnyttjande. Slutligen utvärderas Emballator Växjöplasts nuvarande färdigvarulager sett till aspekterna utifrån analysen för frågeställning 2. Här presenteras även kortsiktiga och långsiktiga förbättringsförslag. Författarna kom fram till följande slutsats: Deras nuvarande förpackning, förvaringsmetod samt artikelplacering tillgodoser respektive bivillkor men kan förbättras sett till the main criteria, volymutnyttjande. Ett kortsiktigt förbättringsförslag genom att utföra en liknande artikelplacering på bättre sätt kan upp till 38-57 fler pallar rymmas på färdigvarulagret. Ett långsiktigt förbättringsförslag genom att kombinera traditionella pallställage och drive-through eller push-back-hyllor, kan totala antal pallplatser på färdigvarulagret öka med 18,4 %.<br>The essay examines how Emballator Växjöplast prioritize and reason among the aspects safety, service level, utilization rate, order picking time and capital tied up in inventory when optimizing their finished goods warehouse. The authors came to the following conclusion: Firstly, they prioritize safety the highest to protect the individuals within the warehouse. Service level is prioritized secondly because they operate with a customer focus. After service level utilization rate is prioritized to lower their need for external storage. Order picking time is prioritized after utilization rate with the goal to avoid the need for employing more operators within the warehouse. Lastly capital tied up in inventory is prioritized because the aspect is not in focus for the logistics department. Moreover, the authors investigate how multi-criteria optimization as an optimization method can be used when optimizing a finished goods warehouse considering several contradictive aspects and the conclusion is: The main criteria method is best suited in optimization method. Utilization rate is the main criteria and the other aspects are constraints. The majority of storage systems and storage assignment policy are within the constraints. The best storage systems and storage assignment policy is therefore mainly determined by the main criteria. Lastly a discussion regarding the finished goods warehouse is held and both short term and long term improvements regarding the aspects are presented. The conclusions made by the authors are as follows: Their current packaging, storage systems and storage assignment policy is sufficient in terms of the different constraints but the main criteria can be improved. Short term improvements are to use a similar storage assignment policy in a better way and enable room for 38-57 more pallets in the finished goods warehouse. Long term improvements are to improve both storage assignment policy and the storage system. By combining traditional racks with some other storage system such as drive-through or push-back-shelves the number of pallets that can fit within the warehouse can increase by 18,4%.
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Mesa, Akhilesh. "A Methodology to Design Systems to Support Fulfillment of Online Grocery Orders." Ohio University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1610708317139122.
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Fjordefors, Julia, and Ali Reanwar Asaad. "Lagerlogistikens betydelse hos företag med begränsad lageryta och hur plocktid kan effektiviseras : En kvalitativ fallstudie hos ett företag med en begränsad lageryta och hur icke-värdeskapande aktiviteter kan reduceras." Thesis, Högskolan i Gävle, Industriell ekonomi, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-36549.
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Many companies do not prioritize warehouse logistics sufficiently in their core business, with the help of increased knowledge, more companies can reduce non-value-creating activities on their warehouse space. There is research and methods designed for standard warehouses that help reduce picking time and non-value-adding activities, however, there is not enough research regarding companies with limited warehouse space and how they can work towards continuous improvement. The purpose and contribution of the study is increasing knowledge of how companies with limited warehouse space can manage and time-efficient their warehouse space with the help of warehouse logistics. A qualitative case study has been performed with observations and an interview where picking time has been the main focus. The collection of the theoretical framework has been reviewed and revised through scientific articles and other literature to strengthen the empirical research. The research is delimited and focuses on limited storage areas. More specifically, the study has placed its emphasis on warehouse logistics and picking time. The study looked at a company's limited storage space and focused on a small part in a delivery, from arrival control to storage. In the empirical study, a case company has been studied and confirmed that warehouse logistics needs to be given better priority in companies with limited warehouse space. With the help of reduced time in warehouse routines, many companies can reduce non-value-creating activities. The purpose of the study and issues will contribute to future research and can be used as a basis. Future research will also help other companies in the same situation to eliminate non-value-adding activities and reduce picking time.<br>Många företag prioriterar inte lagerlogistik tillräckligt i sin kärnverksamhet, med hjälp av en ökad lagerlogistik-kunskap kan fler företag reducera icke-värdeskapande aktiviteter på lagerytan. Det exister forskning och metoder som är utformade för standardlager som hjälper till att reducera plocktid och icke-värdeskapande aktiviteter, däremot saknas det tillräcklig forskning gällande företag med begränsad lageryta och hur dom kan arbeta mot ständiga förbättringar när det kommer till lagerlogistik. Studiens syfte och bidrag ligger i att öka kunskapen om hur företag med begränsad lageryta, med hjälp av lagerlogistik, kan hantera och tidseffektivisera sin lageryta. En kvalitativ fallstudie har utförts med observationer och mejlkommunikation där plocktid varit huvudfokus. Samling av det teoretiska ramverket har genom vetenskapliga artiklar och annan litteratur granskats och reviderats för att stärka den empiriska undersökningen. Forskningen avgränsas och fokuserar på begränsade lagerytor. Mer specifikt har studien lagt sin vikt på lagerlogistik och plocktid. Studien har tittat på ett fallföretags begränsade lageryta och på en liten del i en leverans, från ankomstkontroll till förvaringsförråd. I den empiriska undersökningen har ett fallföretag studerats och bekräftat att lagerlogistik behöver prioriteras bättre hos företag med begränsad lageryta. Med hjälp av reducerad tid vid lagerrutiner kan många företag reducera icke-värdeskapande aktiviteter. Studiens syfte och frågeställningar kommer att bidra till framtida forskningar och kan användas som underlag. Framtida forskning kommer även bidra med att hjälpa andra företag i samma sits att eliminera icke-värdeskapande aktiviteter och reducera plocktid.
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Conneller, Chantal. "Space, time and technology : the Early Mesolithic of the Vale of Pickering, North Yorkshire." Thesis, University of Cambridge, 2000. https://www.repository.cam.ac.uk/handle/1810/272079.
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Chi, Yi-Fan, and 紀奕凡. "The picking time and racking management of automotive parts retailers." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/kmrqvt.
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碩士<br>國立臺北科技大學<br>車輛工程系所<br>99<br>Nowadays automotive parts retailers in Taiwan have experienced several times of
market changing. After changed, they have to face the brand new market which
includes the more brands of vehicle but the less quantity of vehicle. Vice versa, they
have to change the way they used to deal with their inventory to adopt this market
changing.
In the past, retailers in Taiwan were used to have only one picker to be responsible for
inventory management. But this has to be changed they face a more complicate
situation for now. Under this case, we researched the picking time both of the D and H
retailer to figure out and measure thepicking time while their picker do picking from
their own warehouse then analyzed the data we get from them by statistics theory.After
comparison, we have found that automotive retailer actually could save their picking
time by doing racking and inventory management so it is worth for retailers in Taiwan
starting to tidy their goods up on racks in their warehouse.
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Chi, Jui-feng, and 紀瑞峰. "A study of minimizing the order picking time in distribution centers." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/24915135510968579448.
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碩士<br>輔仁大學<br>管理學研究所<br>92<br>Because of the benefits of lowering the inventory level and controlling the distribution channels, many enterprises have devoted to build their self-own distribution centers. And therefore the management and control of the operation in distribution centers (DCs) becomes an important issue. In practice, the main activities in DCs are receipt, storage, order picking and dispatch, and according to the previous literatures, order picking accounts for most of the total operating cost and thus many literatures focused on order picking to enhance the efficiency in DCs.
DCs adopt several kinds of order picking system. The order picking system in this study is mainly to handle the bulk-broken items. In this system all items are picked into containers and containers would be sent by conveyor belt to the next picking zone. In practice the order picking may adopt order split strategy to boost the order picking speed, and because of the adoption of these picking strategies the container of an specific order is separated on different order picking lines hence those separated containers should be accumulated together to form a complete order. In order to accumulate those goods of the same order, there should be a buffer in the tail of the order picking lines to store these goods. And the length of buffer is limited and once the buffer is all used, the order picking line which the buffer belongs to should be stopped to wait the buffer release and the order picking efficiency is reduced. This study shows how the sequence of order picking affects the order picking time (Cmax), and the purpose of this study is to find a order picking sequence to minimize the times of buffer jam and to minimize Cmax .
In practice the there are hundreds of orders and the search space is extremely large, so it is hard to apply the traditional operation research method to find the optimum solution because of the time limit. In this research the genetic algorithm is applied and is implemented with the C language.
The computational results show the improvement to the status quo in different situations is from 2% to 10%. The more the number of orders, the more the number of order picking lines and the shorter the length of buffer, the more the improving rate.
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Wu, Jheng-Jie, and 吳政潔. "A Study on the Real-Time Order-Batching Problem of Order-Picking in Distribution Centers." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/14394870603743892265.
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碩士<br>國立中央大學<br>工業管理研究所<br>95<br>This study deals with the real-time order-batching problem in a warehouse. In real-time order-batching, two or more orders are combined together in one picking list, and composition of the picking list is affected by the picker visiting pick-up point. A designed methodology divides this problem into five sub-problems is proposed. The sub-problems are to orderly determine the initial picking-zone, the appendant picking-zone, the minus items, the select orders, and the picking route. The simulation experience is measured by the total travel distance. We want to understand not only the performance of every main factor but also their combined performance. Different random problems were generated and tested for this purpose. It is hoped that the knowledge learned from this study can provide substantial benefits to practitioners in distribution centers.
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Tsai, Hui-ching, and 蔡惠菁. "Expected travel time model for the optimal order picking sequence in an automated carousel system." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/69181219801269211569.
Full textAbstract:
碩士<br>國立成功大學<br>工業與資訊管理學系碩博士班<br>96<br>We consider the expected travel time model for the optimal dynamic order picking problem in a closed loop carousel convey. In this order picking system that is very popular for the small to medium sized items, the carousel rotates clockwise orcounterclockwise, and the item travels to the picker for the retrieval. This allows the picker to perform other tasks such as pack, label, process other items, when the carousel rotates. The concurrency of activity enables great retrieval and throughput performance.
The carousel order picking system is used to process a sequence of orders from customers in a dynamic fashion. Each order includes one or several items to be picked from the carousel storage or bins. The sequence among the items within an order is to be determined to minimize the total order processing cost or time. Based on the dominance condition of the optimal picking sequence, the expected travel time model to pick an order with several items is developed.
Computational experiments are performed to compare the performance of the expected travel time model with the simulation model, where the continuous model is used for devising the expected travel time, while a discrete number of storage bins is used in the simulation model. It has been shown that the model performs very well with average percentage deviation being 1.18%. It is also observed that the performance of the continuous model improves the number of bins increases.
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Valero, Cano Eduardo. "Arrival-time picking methodology using fuzzy c-means and Akaike information criterion for downhole microseismic data." Thesis, 2019. http://hdl.handle.net/10754/655681.
Full textAbstract:
Microseismic monitoring is a valuable technique to locate and characterize frac-
tures in unconventional reservoirs. The monitoring is usually carried out from a large
surface array of vertical-component receivers or a short downhole array of three-
component receivers. For a downhole array, P- and S-wave arrival-time picking is
typically required to process the microseismic data. Furthermore, arrival-time pick-
ing is done automatically considering the large volumes of microseismic data.
In this work, I propose a new methodology for automatic picking of P- and S-
wave arrivals of microseismic events recorded by downhole arrays. The methodology
consists of three steps: (1) For a single trace, intervals of possible arrivals are detected
using the conditional fuzzy c-means (CFCM) method. (2) These intervals are further
classi_ed into representing a P wave or an S wave using the information obtained
from polarization analysis. (3) The Akaike information criterion (AIC) picker is then
used on the P- and S-wave intervals to pick the corresponding arrival times. To
automatically validate the arrival picks, I test the Random-sampling-based Arrival
Time Event Clustering (RATEC) method.
The proposed methodology was tested on a real downhole microseismic data set
and was compared using fuzzy c-means (FCM) and with the short-term average over
long-term average (STA/LTA) method. To evaluate the automatic picking, manual
picks were used as a reference. For a time tolerance of ±5 ms, the percentage of correct
P- and S-wave arrival picks was 81% and 82% for the FCM methodology, and 77%
and 75% for the CFCM methodology. The STA/LTA was used to pick only P-wave
arrivals; it obtained 60% of correct picks. The RATEC method was used to vali-
date the arrival picks obtained by the FCM methodology. The percentage of correct
classi_cations was 93% and 87% for the P- and S-wave arrival picks respectively.
Based on the real data results, the best picking performance of the proposed
methodology is achieved using FCM. The FCM methodology is more robust to de-
tect and pick arrivals than the STA/LTA method. Additionally, the straightforward
implementation of the FCM method and AIC picker make the FCM methodology
implementation relatively simple.
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Ting-Mei, Huang. "Using A Multiple-GA Approach to Solve Batch-picking Problem: Considering the Travel Distance and Order Due Time." 2006. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0009-2507200610301300.
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陳彥旭. "Infuence of Picking Condition、Material on the Flying Time of Weaving and the Amount of Yarn by W.J.L." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/71671788044581181773.
Full textAbstract:
碩士<br>逢甲大學<br>紡織工程學系<br>88<br>Abstract
The demand of Tusakoma Water Jet Loom in manufacturing industry is on the increase. This research studied the best process of picking condition and the amount of yarn.
The purpose of this research was to study the best process of weaving and the amount of the conditions of picking by different kinds of wefts (such as, water pressure, water amount, opening degree, diameter of nozzle, tension of warp) tested the change of compulsory angle, yarn diameter and the contraction rate of warp and weft yarn. We obtained an correct range of compulsory angle. Then, according CNS to test the quality of cloth. We observed the best picking conduction by the result of testing the CV % of weft-lose-yarn length. Finally, estimated the yarn diameter of cloth under the microscope, a mathematical equation that defines the relationship between yarn diameter and shedding time was found by regression equation. Adding the diameter formula into the fractional cover formula, a relation formula of fractional cover between contraction rate was found by regression equation. According this contraction rate formula and the amount yarn formula, we observed a practical formula to the amount of yarn.
Experimental results were as follows; shedding time and compulsory angle were decreased as the water amount、
water pressure and diameter of nozzle increased; however,
shedding time and compulsory angle were decreased as well as opening degree decreased. Weft diameter、tension of picking 、fractional cover were increased when the water pressure、water amount and diameter of nozzle increased; however, weft diameter、covering rate were increased as the opening degree decreased. Weft contraction rate was decreased as the water pressure 、water amount and diameter of nozzle increased; however, it was decreased as well as the opening degree decreased.
The study including both practical technology and theoretical ratiocination. It provides directions for W.J.L. the best process of picking special weave fabric. It also has made the contribution to provide manufactures the information about the correct amount of yarn 、how to improve the quality of cloth and how to reduce the production cost.
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Huang, Ting-Mei, and 黃婷媺. "Using A Multiple-GA Approach to Solve Batch-picking Problem: Considering the Travel Distance and Order Due Time." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/80821482012937444918.
Full textAbstract:
碩士<br>元智大學<br>工業工程與管理學系<br>94<br>Warehouse management is one of the critical keys to strengthen company logistics. Effective batch picking operations can increase the productivity of a warehouse. To attain better batch picking efficiency, previous researches mainly focus on the problems of smaller order size and specific warehouse layouts. In addition, their methods either consider travel cost or earliness and tardiness penalty separately. These drawbacks make these methods hard to be adopted in current complex and quick-response oriented environment.
In this thesis, we develop a multiple-GA (Genetic Algorithm) method, which consider both travel cost and earliness and tardiness penalty, for automatically grouping the required items into batches to solve the complex batch picking problem in the warehouse systems. Performance comparisons between the proposed multiple-GA approach and other two heuristic methods are given for various problems including small-, medium- and large-size batch picking problems. Based on the experiment result, the proposed multiple-GA approach is more effective in solving the batch picking problems in terms of solution quality.
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Jang, Hung-Wei, and 張鴻偉. "Part-Time Human Resource Strategy for Picking Operation in Distribution Center. A Case Study Pin Tai Distribution Enterprise Co., Ltd." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/25852284305447520692.
Full textAbstract:
碩士<br>國立高雄第一科技大學<br>運輸與倉儲營運系<br>88<br>Accounting for 40% of total cost for distribution center (DC), picking operation is the most critical part of DC operations. To improve performance of picking operation, reasonable human resource strategy could play a decisive factor towards successful operations. Employing part-time workers attached with the piecework plans can be a pertinent strategy which can reduce the impact resulting from the seasonal fluctuation of business and inspire part-time workers’ productivity. Two variables, ‘the ratio of part-time staff’ and ‘the ratio of part-time piecework’, therefore are two decisive factors for the issue of part-time human resource strategy.
Thus, this study re-explores the performance indexes for picking operation, based on the principles of comprehension, exclusion, and simplification, and develops the performance indexes of picking operation in the aspects of effectiveness, efficiency, and equity. In this study, the indexes are investigated and justified that effectiveness is represented by two indexes: “rate of picking mistake” and “flexibility of staffing allocation”; while efficiency is represented by the index of “the number of picking item per staff per hour”; and, equity is by “ ratio of salary of full-time staff to that of part-time staff” given an identical production”. This study applies two variables mentioned earlier, ‘the ratio of part-time staff’ and ‘the ratio of part-time piecework’, as the decision variables of human resource strategy, thereby establishes a quantitative model linking the established indexes and decision variables. In considering the theory of the learning curve, the function form is assumed to be non-linear, and the models are tested and calibrated by the corresponding data provided by Pin-Tai Distribution Enterprise Co., Ltd.
The results indicate that the indexes of effectiveness and efficiency are significantly affected by two decision variables, while that of equity is only significantly by the ratio of part-time piecework. By analyzing the quantitative results, this study finally proposes two optimal human resource strategies for attaining the future targets set by the DC company in accordance with the condition of the exterior employment market.
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Gonçalves, Telma Sofia Matos. "Análise e melhoria de operações de um armazém JIT: caso de estudo." Master's thesis, 2014. http://hdl.handle.net/10362/14250.
Full textAbstract:
A globalização apresenta inúmeros desafios à gestão da cadeia de abastecimento ao facilitar e promover um contexto de intensa competitividade. Atualmente os armazéns são um meio para as organizações obterem vantagem competitiva através da redução de custos e do aumento da capacidade de resposta ao mercado, cada vez mais volátil.
Esta dissertação, desenvolvida num armazém pertencente ao Grupo Jerónimo Martins que funciona segundo a filosofia Just-In-Time, tem como objetivo melhorar o desempenho do armazém através da identificação de problemas e proposta de soluções, com base nos conceitos ao Toyota Production System.
Foram identificados problemas ao nível dos fatores humanos, da falta de flexibilidade de algumas operações e dos desperdícios do tipo Muda e Muri. As principais propostas de melhoria baseiam-se na eliminação de Muda. Foram identificadas as atividades que não acrescentam valor e sugerida a sua eliminação. É analisada a sobreposição de tarefas de suporte com as tarefas produtivas, através de voice picking e da utilização de motas com controlo remoto, com esta última a apresentar uma redução do custo anual até 18% nas movimentações de acessórios de transporte na zona de execução. É apresentada uma proposta para a redução do manuseamento dos produtos através do aumento em cerca de 129% do número de contentores completos executados e sugerida a definição de uma função de transferência que visa reduzir o custo de transporte através do aumento da taxa de ocupação dos acessórios de transporte. Finalmente, para mitigar o principal desperdício identificado, a distância percorrida, foi proposto um novo layout do armazém que permitiu uma redução de aproximadamente 21% do custo de movimentação de acessórios de transporte entre diferentes zonas do layout.
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Calva, Cíntia Nabais Armindo da. "Avaliação do desempenho logístico do armazém da Bourbon Automotive Plastics." Master's thesis, 2020. http://hdl.handle.net/10400.8/4970.
Full textAbstract:
Com o ambiente cada vez mais competitivo que se vive dentro das empresas, estas
são obrigadas a ter especial atenção à gestão das atividades logísticas e à redução dos custos
operacionais. Neste âmbito, têm sido desenvolvidos inúmeros estudos com o objetivo de
melhorar a eficiência e eficácia das decisões logísticas e a avaliação do desempenho das
atividades logísticas.
No presente projeto, foi realizado um amplo trabalho de pesquisa sobre os temas da
metodologia just-in-time, da gestão logística e da avaliação do desempenho logístico. O
presente projeto foi acolhido pela empresa Bourbon Automotive Plastics (Bourbon AP). Em
articulação com a mesma, foi possível rever os indicadores de desempenho presentemente
utilizados pela empresa na avaliação do desempenho do armazém em contexto de gestão
logística, e propostos novos indicadores, incluindo o planeamento da sua implementação,
em resposta a um conjunto de necessidades levantadas pela empresa em termos de
informação necessária, e atualmente inexistente, para apoiar as atividades de planeamento,
tomada de decisão e monitorização do desempenho do funcionamento do armazém.
Foi igualmente efetuado um trabalho de campo de medição de alguns dos novos
indicadores propostos, após ter sido manifestada pela empresa a necessidade urgente em
utilizar a respetiva informação para apoio ao planeamento semanal operacional do armazém,
em particular a nível do planeamento de afetação de recursos humanos às tarefas de
preparação das paletes para expedição. Em detalhe, recolheram-se dados relativos aos
tempos de preparação para expedição dos diferentes tipos de paletes utilizados pela empresa,
que permitem um apuramento mais rigoroso das necessidades de horas de trabalho do
armazém para as tarefas de expedição.
Em termos de resultados, entende-se que o presente projeto contribuiu para melhorar
o sistema de avaliação de desempenho logístico dos armazéns da empresa Bourbon AP, cujo
processo de produção se baseia na metodologia just-in-time e em conceber o produto certo,
no lugar certo, com a qualidade certa, na hora certa, na quantidade certa, para o cliente certo.
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Chinag, Shu-Chun, and 江淑君. "DDT:refraction statics correction without picking first arrival times." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/13199379847664980001.
Full textAbstract:
碩士<br>國立中央大學<br>地球物理研究所<br>91<br>ABSTRACT
A differential delay time (DDT) concept is proposed for refraction static correction without picking first arrival times in the CDP reflection data processing. This new method is a modification of the ABCD method; it uses cross-correlation to measure the first arrival time difference between signals received at stations B and C, instead of directly computing them from their picked times. By taking advantage of multiple-fold CDP data, we apply the super trace measurement, which may alleviate the effect of data imperfections.
As alike as the ABC method, we fill the traveltime differences in a matrix with the reciprocal method concept in DDT method, then the matrix is inverted to solve for the refraction velocity and weathering depth by a inversion method. Finally, we can get the static correction value converted by the refractor model. A synthetic model and a real case with a severe weathered layer problem have been tested to evaluate the method. Stable and manageable computation processes have been explored to attain maximum performance. The results are quite satisfactory.
In the theory, the DDT method combines “delay time” concept of refraction with multiple fold of CDP data. In application, we can handle the data with DDT method automatically. This is very objective and convenient. Now we apply the DDT method to general shadow CDP seismic reflection cases and the results are very good. This method is worth using widely.
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Chen, Wei Kuang, and 陳瑋光. "Chutnification of History and Pickling of Time: Bodily Reinscription in Salman Rushdie’s Midnight’s Children." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/55818391111439808527.
Full textAbstract:
碩士<br>國立暨南國際大學<br>外國語文學系<br>100<br>This thesis explores the alternative historiography of modern Indian history in Salman Rushdie’s Midnight’s Children. The protagonist Saleem’s chutnification of history and pickling of time become a philosophy of history in which the alternative genealogy challenges not only official history but also the myth of origin. Chapter one develops the notion of history in genealogical framework in Salman Rushdie’s Midnight’s Children, especially through the perspective of the protagonist Saleem Sinai. The construction of alternative genealogy suggests historical disparity buried under the master narrative of national documentations and exposes the fictionality of the myth of origin. The point of alternative genealogy is to explore the discordant nature of time in narrative, and therefore to reach the effects of interrogating historical truth and uncovering possible ways of interpretation of history at the same time. Chapter two explores the relation between body and history, and supposes that the body serves as the inscribed surface of history. When the body is deformed under historical violence and becomes grotesque, it shows the image of India’s pathological history and reflects the grotesque realities of the larger body of community with physical diseases. The supposition looks for the symbolic signification on the grotesque body outside linguistic construction and examines how the grotesque body becomes the prime agent of the interactive process between individual body and public history.
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El-Khatib, Mayar. "Highway Development Decision-Making Under Uncertainty: Analysis, Critique and Advancement." Thesis, 2010. http://hdl.handle.net/10012/5741.
Full textAbstract:
While decision-making under uncertainty is a major universal problem, its implications in the field of transportation systems are especially enormous; where the benefits of right decisions are tremendous, the consequences of wrong ones are potentially disastrous.
In the realm of highway systems, decisions related to the highway configuration (number of lanes, right of way, etc.) need to incorporate both the traffic demand and land price uncertainties. In the literature, these uncertainties have generally been modeled using the Geometric Brownian Motion (GBM) process, which has been used extensively in modeling many other real life phenomena. But few scholars, including those who used the GBM in highway configuration decisions, have offered any rigorous justification for the use of this model.
This thesis attempts to offer a detailed analysis of various aspects of transportation systems in relation to decision-making. It reveals some general insights as well as a new concept that extends the notion of opportunity cost to situations where wrong decisions could be made. Claiming deficiency of the GBM model, it also introduces a new formulation that utilizes a large and flexible parametric family of jump models (i.e., Lévy processes). To validate this claim, data related to traffic demand and land prices were collected and analyzed to reveal that their distributions, heavy-tailed and asymmetric, do not match well with the GBM model. As a remedy, this research used the Merton, Kou, and negative inverse Gaussian Lévy processes as possible alternatives.
Though the results show indifference in relation to final decisions among the models, mathematically, they improve the precision of uncertainty models and the decision-making process. This furthers the quest for optimality in highway projects and beyond.