How to evaluate mutual fund performance correctly and determine the investment targets of mutual funds are the important issues to investors. In this study, we apply an innovative bootstrap statistical technique, to solve the small sample size problem and the distribution assumption disturbance in previous research. We examine the performance of domestic open-end mutual funds over the period from 1998 to 2003 using five performance measurement models. We further test the persistence of mutual fund performance. This study shows that¡G 1. On average, mutual fund managers do not own superior ability in stock selection. Most funds experiencing abnormal performance may simply result from good luck, since random selection also creates abnormal performance. 2. Mutual fund managers do not own market-timing ability. Classified further by investment objectives, the sample indicates that only the group of small-scale stocks shows significant market-timing ability. 3. Performance persistence does not exist no matter in long-term or short-term period.

Logistics makes extensive use of human and material resources to achieve a target level of customer service at the lowest possible cost. It has been recognized as a major key to success in commerce and industry, and continues to evolve radically and grow in importance in recent years. Warehousing, as one of the most costly elements of logistics, is often the central operation in most logistics networks. Its successful management is critical in terms of both cost and service. In this thesis, two problem areas in warehouse logistics are studied: stock loading and order picking. Stock loading is an essential operation in modern logistics. Improvement on container capacity utilization and loading efficiency significantly reduces costs. For a given set of boxes in different sizes and an unlimited number of identical containers, the basic cargo loading problem is to determine the minimum number of containers required. The problem is proven NP-hard. To tackle this problem, a Tabu search optimization with a tree-based cargo loading algorithm as its inner heuristic is proposed. This approach has flexibility in taking different box conditions into consideration, and can find better solutions on average than other recent meta- or heuristic algorithms. Decreasing order sizes and increasing fuel costs provide a strong incentive for the inner-city truck loading operation to utilize container space more efficiently in transporting goods to multiple clients during one trip. This considers not only traditional loading constraints, but also multi-drop requirements. A wallbuilding heuristics based on a binary tree data structure is proposed to handle these side constraints. A dynamic space decomposition approach, together with a repacking and space amalgamation strategy, permits an efficient and effective loading plan. Order picking, one of the most critical warehousing operations, is the second problem studied in this thesis. An analytical approximation model is proposed based on probability modeling and queueing network theory applied to a synchronized zone picker-to-part order picking system with different routing and ABC-class inventory storage policies. The numerical results are compared and validated via simulation. The resulting model can therefore be usefully applied in the design and selection process of order picking systems. The routing versus storage issues are further investigated with a simulation model. This extends the existing research by evaluating multiple routing and storage policies under varying operating conditions. Results show that the midpoint, return and traversal routing policies generally perform best when paired with perimeter, across-aisle and within-aisle storage strategies, respectively. Yet performance is indeed dependent on demand patterns, zone sizes, batch sizes and order sizes. At first glance, order picking and stock loading operation seem to pursue different objectives. However, they are two related operations conducted sequentially from internal to the outbound side of warehousing. An efficient order picking system is a precondition for an effective loading operation at the shipping dock, especially when multiple orders need to be selected for consolidation in shipment. The proposed loading algorithms and the order picking system performance evaluation models can be used to further study the effective integration of these two functions. / published_or_final_version / Mathematics / Doctoral / Doctor of Philosophy

No description available.

Thesis (M.S.)--Ohio University, November, 2002. / Title from PDF t.p.

Ingeniero Civil Industrial / El presente trabajo de título corresponde al rediseño del proceso de pedidos y despacho de alimentos del cliente de Compass Catering S.A. de la empresa chilena Keylogistics, y está enfocado en mejorar el servicio otorgado al cliente, para así aprovechar de mejor forma los recursos utilizados en el proceso. Este rediseño se basa en un problema descrito por la organización Keylogistics (operador logístico). Donde se estudiarán procesos del cliente Compass (empresa de Catering), que pide alimentos para distribuir a cada uno de sus casinos. Específicamente, el problema se genera en los pedidos para sectores remotos -principalmente faenas mineras-, generando problemas frecuentes al momento de consolidar los pedidos en pallets y verificar si realmente cabe, o no, en los camiones asignados para el despacho. Recurrentemente la carga no cabe en los camiones, o por el contrario, cabe, pero se pierde mucho espacio. También, se trabajó en un problema con el manejo y respuesta a reclamos y no conformidades, generando una solución que busca encontrar la causa raíz de los requerimientos del cliente y solucionarlos con el objetivo de que no vuelvan a ocurrir en el futuro. Esta memoria tiene como objetivo general, identificar la causas con mayor incidencia en las entregas no conformes, para así proponer medidas que mejoren la logística del proceso de despacho del cliente Compass, aumente el porcentaje de efectividad en la entrega, disminuyan los errores en documentación, generar una mejor planificación, administrar el manejo de reclamos y optimizar el uso de recursos en la operación. Como conclusión luego del desarrollo del proyecto, se determina que la implementación del rediseño en el proceso de picking y despacho, el software cubicador y la plataforma Weflow son viables, generan beneficios económicos y mejoras en la percepción del cliente sobre el servicio entregado y ya están desarrollados los prototipos funcionales para facilitar el plan de implementación propuesta del rediseño realizado.

O presente trabalho trata da determinação de um roteiro ótimo de separação manual de peças em armazéns, buscando a minimização da distância total percorrida. São considerados armazéns com dois corredores transversais localizados em suas extremidades, os quais conectam todos os corredores de separação, perpendiculares aos corredores transversais e paralelos entre si. O problema abordado é prático e comum a várias empresas, com impacto nos custos operacionais e relevância para a assertividade em relação aos itens coletados. Ainda assim, o tema é pouco explorado nos estudos de roteirização disponíveis em língua portuguesa e muitas empresas optam por confiar a criação das rotas aos próprios separadores. O método escolhido é baseado em programação dinâmica e foi aplicado na roteirização de listas de separação relacionadas a subconjuntos do produto final, na roteirização de grupos aleatórios de peças, e no estudo do impacto do número de corredores de separação no comprimento das rotas, totalizando 184 experimentos. A forma de avaliação do algoritmo foi comparar as rotas por ele criadas com aquelas criadas pelos separadores. Conclui-se que quanto mais complexa for a rota, maiores serão os ganhos da seqüência de coletas proposta pelo sistema em comparação com aquelas criadas por processos subjetivos. Concluiu-se também que o número de corredores a ser visitado é o fator que mais influencia no comprimento da rota a ser percorrida. Ainda, o algoritmo é flexível e genérico para ser utilizado em qualquer armazém com dois corredores transversais, independente da política de localização ou separação adotada e, por sua facilidade de implementação e utilização, representa uma alternativa de roteirização eficiente e de baixo custo para pequenas e médias empresas. Finalmente, tem-se um algoritmo que pode ser utilizado também como ferramenta gerencial e de simulação visto que pode ser configurado para diferentes leiautes e diferentes tamanhos listas de separação. / The present work deals with the shortest route creation for a low-level pickers-to-part warehouse, intending to minimize the total traveled distance. The considered warehouse has two traversing aisles, located in its extremities, connecting all of the picking aisles and perpendicularly set in relation to them. The proposed problem is practical and common to several companies, impacting their operational costs and important for mis picking reduction. Nevertheless, that theme is little explored among routing studies in Portuguese language and several companies still opt to trust the routes to be subjectively prepared by their own pickers. The proposed solution method is based on dynamic programming and it was applied in the routing of picking lists related to subsets of final products, random groups of items, and in the study of the impact that picking aisle quantity has on the total length of the routes, totaling 184 experiments. The proposed algorithm was evaluated comparing the routes prepared by it with those created by the pickers. Results show that the more complex the route is, the higher the earnings of the algorithm utilization in relation to the subjective processes will be. Besides it shows that the number of corridors to be visited is the main influence to the length of the route. Still, the algorithm is flexible and generic to be used at any warehouse with two traverse corridors, independent of the locating police or separation strategy adopted. Furthermore the algorithm implementation easiness and use support it to be an efficient low cost routing alternative for small and average size companies.

No description available.

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.

The thesis deals with ways of increasing efficiency in retail with focus on logistics from theoretical as well as practical perspective. Application of the practical part is demonstrated on the example of Dotcom, online store project of Tesco Stores ČR a.s. First aim of the thesis is to identify areas with the biggest potential in increasing efficiency with respect to financial demands of the eventual investment and to propose a potential solution. Second aim is to verify a hypothesis that the delivery of goods to customers is inefficient given that the planning system is not being linked to the tracking system.

Las empresas comercializadoras mayoristas se vienen enfrentando a nuevos retos en cuanto al nivel de servicio, el cual es un factor importante y el que determina el nivel de ventas y la rentabilidad de las empresas. Es así que, actualmente, las empresas se rigen a entregar los pedidos a sus respectivos clientes a tiempo, en buen estado y completos. Este documento se centra en la importancia de la gestión de almacenes para las distribuidoras de consumo masivo, ya que son los almacenes los que determinan los costos de operación y productividad de estas. Es así que algunas técnicas innovadoras como el lean warehouse y herramientas de asignación, mejoran las condiciones de trabajo con el objetivo de reducir tiempos muertos y distancias. Se llevó a cabo un piloto de implementación de las herramientas mencionadas en el almacén de una distribuidora mayorista. Como resultado de la investigación se logró la reducción de la distancia recorrida en almacén en un 22%, la reducción de tiempos en el proceso de picking, logrando el tiempo óptimo de entregas y generando un incremento de las ventas efectuadas de 215,720.22 soles. Estos resultados demuestran ser determinantes en el rendimiento de la cadena de suministro (inventario, costo, retraso y riesgo), ya que la clave del éxito para esta industria es satisfacer las necesidades de los clientes en el menor tiempo posible. La presente investigación se justifica en la necesidad de incrementar la productividad dentro de una empresa distribuidora de productos de consumo masivo, mejorando los procesos claves de la misma. Esto con el objetivo de contribuir al crecimiento de la rentabilidad de la empresa. / The wholesale trading companies are facing new challenges in terms of the level of service, which is an important factor which determines the level of sales and profitability of companies. Thus, currently, companies are aimed to deliver orders to their respective customers on time, in good condition and complete. This file focuses on the importance of warehouse management for mass consumption distributors, since it’s the warehouses that determine the operation and productivity costs of these. Thus, some innovative techniques such as the lean warehouse and allocation tools improve working conditions with the aim of reducing downtime and distances. A pilot programme of implementation of the tools mentioned in the warehouse of a wholesale distributor was carried out. As a result of the research, the distance traveled in the warehouse was reduced by 22%, the reduction of times in the picking process, achieving the optimal delivery time and generating an increase in the sales made of 215,720.22 soles. These results prove to be decisive in the performance of the supply chain (inventory, cost, delay and risk), since the key to success for this industry is to satisfy the needs of customers in the shortest possible time. This research is justified in the need to increase productivity within a company that distributes consumption products, improving its key processes. This with the objective of contributing to the growth of the profitability of the company. / Tesis