Study of the Transferability of Properties used for designing Production Systems layouts to distribution warehouse layout design.

International audienceThe performance of distribution warehouses plays an important role in the global performance of any Supply Chain. Logistic services providers need to plan the layout evolution of the physical system they manage to adapt to their customers' requests. A clear, global and detailed vision of logistic activities is therefore necessary. A considerable amount of research has been conducted on the design of production systems. This article proposes a study of the transferability of certain production system design properties to distribution warehouse design

A holistic conceptual model for managing construction logistics in building projects: the case of Iran

Logistics, as a factor that affects the total cost of a product, has attracted attention in many industries. However, construction is behind other industries, such as manufacturing and food, in terms of obtaining value through application of effective logistics management. Some specific characteristics of the construction industry, such as fragmented supply chain, indirect employment, temporary location and matchless products, have prevented organisations utilising logistic management in their projects. In construction, logistics is about the mobilisation of different types of resources to feed the project with the required materials and components at the right time, in the right place, right quantity and right quality. To do so, a new approach to construction logistics should be undertaken that respects the special characteristics of this industry. This research aims to develop a conceptual model based on the current practice of construction logistics in building projects. This model, in addition to complying with the special characteristics of the construction industry, is also adapted to the economic, cultural, technological and environmental specifications of the building sector in Iran. The complexity mindset is adopted in this research which allows considering a construction logistics system as a whole and the system may assert an aggregate behaviour. This approach is called holism and investigates the performance of complex adaptive systems. The study is focused on the Iranian construction industry as the main source of data collection. To achieve the aim and objectives of the research, a literature review was followed by qualitative and quantitative data collection. This research adopted the complementarity approach that uses qualitative and quantitative strategies in a way that complement each other. In the qualitative phase, twenty four open-ended interviews were conducted with construction practitioners who work in the building sector in Iran. Gathered data was analysed using NVivo. This involves codifying the textual data to find themes, categories and relationships. The results of the first phase were rich and exploratory and explained opinions, norms and attitudes. Based on the results of the first phase, a questionnaire with ten sections was designed to investigate different aspects of construction logistics from wider perspectives by conducting a survey on a large sample. The data gathered from the second phase were analysed in a descriptive manner to provide statistical information about the present practice of construction logistics in the Iranian building sector. The final product of this research is a holistic conceptual model that has four subsystems: (a) environmental factors (b) operational factors, (c) commercial factors, and (d) managerial factors. Each subsystem has several agents that are different functions of logistics in a building project. The environmental factors include project size and location, peak working seasons, resource conservation and weather conditions. The operational factors discuss technological matters, construction methods, new materials, waste and transportation. The commercial factors encompass the supply chain, finance, economic conditions, material costs, estimation, supplier selection, packaging, purchasing, inspection, and material quality. The managerial factors cover material management, warehousing, material handling, information management, scheduling, delivery, organisation, personnel, knowledge, culture and site layout designing. All of these functions are integrated under the topic of construction logistics model. The model also illustrates the relationships among agents of the system. The developed model, in addition to technical factors, has paid attention to soft factors such as culture, economy and knowledge. The model is adaptable to changing environments and elements may be added or deleted from the system whenever required

Developing a Decision Support Tool for Increased Warehouse Picking Efficiency

Problem description: Warehousing is central in order to achieve a competitive supply chain, and considered essential for the success, or failure, of businesses today. In general, warehouses account for a large share of the company logistics costs. Consequently, there is a need for warehouses to operate smoother, faster and more accurate. Within warehousing, the most labor-intensive and costly warehouse operation is order picking, this is mainly due to the large amount of travelling involved. All articles included in this study agree that order picking account for at least 50 percent of warehouses' total operating costs. Warehouses thus carry great potential to justify the expenses they bring through reducing the time spent on activities that are not value adding. Purpose: The overall goal in this thesis is to provide guidance for how a warehouse can operate more efficient by improving its picking performance, which also includes reviewing the closely interlinked warehouse operations storage allocation and routing. Research questions: How can a decision support tool for reviewing the choices of storage allocation, order picking, and routing methods in manual warehouse operations be put together in a structured way? Which features should be considered in the decision support tool for choosing methods for improving warehouse operations? Methodology: The guidance for improved picking performance was framed into a decision support tool building on a thorough review and analysis of the research available in the area. A case study on picking efficiency was conducted in order to create a deep understanding for the issues and challenges that prevail in warehousing, and also to ensure that the final recommendations and the answers to the research questions have good support in academia. Once the tool was created, an illustrative example was used to demonstrate the use of the tool on a more detailed level and to test its comprehensibility and usability. Conclusions: In many areas, the resulting tool manages to provide unequivocal guidance for how to improve a warehouse’ picking operations. Multiple features are identified as important for the decision process; among those are demand skewness, seasonality among different SKUs, total demand variation and pick list size. Company objectives and priorities were also identified as a central feature due to the interrelatedness of the decisions connected to picking and their well-known tradeoffs. The research is however sometimes scarce, and further studies need to be carried-out in order to complement and level the strength of the tool.Problembeskrivning: Lagerverksamhet utgör en central del i att uppnå en konkurrenskraftig försörjningskedja och betraktas som direkt avgörande för ett företags framgång, eller utebliven sådan. Det är en dyr verksamhet, och en stor del av ett företags totala logistikkostnader kan hänvisas direkt till lagret. Följaktligen finns det ett behov för lager att prestera jämnare, snabbare och mer precist. Orderplockning är den tveklöst kostsammaste och mest resurskrävande lageraktiviteten. Den huvudsakliga anledningen är att orderplockning till stor del består av transporter mellan platser, vilket inte i sig tillför något värde och därmed enbart är resurskrävande. Alla vetenskapliga artiklar som är inkluderade i studien är eniga om att minst 50 procent av ett typiskt lagers driftkostnader kan härledas till orderplock. Lagret har därmed stor potential att rättfärdiga sina kostnader, genom att reducera den andel tid och resurser som läggs på icke värdeskapande aktiviteter. Syfte: Det övergripande målet med uppsatsen är att skapa vägledning för hur lager kan öka sin effektivitet genom att förbättra sina plockprocesser. Detta inkluderar även de närliggande beslutsområdena lagerplatsallokering och ruttplanering. Forskningsfrågor: Hur kan ett beslutsverktyg för att granska metodval för lagerplatsallokering, orderplockning och ruttplanering vid manuell lagerverksamhet sättas ihop på ett strukturerat sätt? Vilka egenskaper bör beaktas i ett beslutsverktyg för att välja metoder som förbättrar lagerverksamheten? Metod: Beslutsverktyget skapades utifrån en grundlig genomgång samt analys av den forskning som finns inom området. En fallstudie om effektivisering av plockhantering genomfördes med syftet att skapa en djupgående förståelse för de problem och utmaningar som förekommer i en lagerverksamhet, liksom att säkerställa att de slutgiltiga rekommendationerna och svaren på forskningsfrågorna var väl förankrade i akademin. När verktyget var skapat användes ett illustrativt exempel för att demonstrera dess användning på en detaljerad nivå, samt för att testa hur lätt det är att förstå och använda. Slutsats: Beslutsverktyget som skapats lyckas ge tydliga rekommendationer och vägledning inom många områden för hur ett lagers plockprocesser kan förbättras. Flera egenskaper identifieras som särskilt viktiga att beakta i beslutsprocessen; bland annat skevhet i efterfrågan, säsongsförknippad efterfrågan mellan olika lagerplatsenhet, total variation i efterfrågan samt längden på plocklistorna. Företags egna mål och prioriteringar identifieras också som centrala i beslutsverktyget eftersom alla beslut är tätt sammanvävda och generellt innebär ständiga kompromisser. Inom flera områden relaterade till plockhantering visade sig forskningen emellertid vara otillräcklig, och ytterligare studier krävs för att stärka beslutsverktyget

Capacitive power transfer for maritime electrical charging applications

Wireless power transfer can provide the convenience of automatic charging while the ships or maritime vehicles are docking, mooring, or in a sailing maneuver. It can address the challenges facing conventional wired charging technologies, including long charging and queuing time, wear and tear of the physical contacts, handling cables and wires, and electric shock hazards. Capacitive power transfer (CPT) is one of the wireless charging technologies that has received attention in on-road electric vehicle charging applications. By the main of electric fields, CPT offers an inexpensive and light charging solution with good misalignment performance. Thus, this study investigates the CPT system in which air and water are the separation medium for the electrical wireless charging of small ships and unmanned maritime vehicles. Unlike on-road charging applications, air or water can be utilized as charging mediums to charge small ships and unmanned maritime vehicles. Because of the low permittivity of the air, the air-gapped capacitive coupling in the Pico Farad range requires a mega-hertz operating frequency to transfer power over a few hundred millimeters. This study examines an air-gapped CPT system to transfer about 135 W at a separation distance of 50 mm, a total efficiency of approximately 83.9%, and a 1 MHz operating efficiency. At 13.56 MHz, the study tested a shielded air-gapped CPT system that transfers about 100 W at a separation distance of 30 mm and a total efficiency of about 87%. The study also examines the underwater CPT system by submerging the couplers in water to increase the capacitive coupling. The system can transfer about 129 W at a separation distance of 300 mm, a total efficiency of aboutapproximately%, and a 1.1 MHz operating efficiency. These CPT systems can upscale to provide a few kW for small ships and unmanned maritime vehicles. But they are still facing several challenges that need further investigations

Application of lean scheduling and production control in non-repetitive manufacturing systems using intelligent agent decision support

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Lean Manufacturing (LM) is widely accepted as a world-class manufacturing paradigm, its currency and superiority are manifested in numerous recent success stories. Most lean tools including Just-in-Time (JIT) were designed for repetitive serial production systems. This resulted in a substantial stream of research which dismissed a priori the suitability of LM for non-repetitive non-serial job-shops. The extension of LM into non-repetitive production systems is opposed on the basis of the sheer complexity of applying JIT pull production control in non-repetitive systems fabricating a high variety of products. However, the application of LM in job-shops is not unexplored. Studies proposing the extension of leanness into non-repetitive production systems have promoted the modification of pull control mechanisms or reconfiguration of job-shops into cellular manufacturing systems. This thesis sought to address the shortcomings of the aforementioned approaches. The contribution of this thesis to knowledge in the field of production and operations management is threefold: Firstly, a Multi-Agent System (MAS) is designed to directly apply pull production control to a good approximation of a real-life job-shop. The scale and complexity of the developed MAS prove that the application of pull production control in non-repetitive manufacturing systems is challenging, perplex and laborious. Secondly, the thesis examines three pull production control mechanisms namely, Kanban, Base Stock and Constant Work-in-Process (CONWIP) which it enhances so as to prevent system deadlocks, an issue largely unaddressed in the relevant literature. Having successfully tested the transferability of pull production control to non-repetitive manufacturing, the third contribution of this thesis is that it uses experimental and empirical data to examine the impact of pull production control on job-shop performance. The thesis identifies issues resulting from the application of pull control in job-shops which have implications for industry practice and concludes by outlining further research that can be undertaken in this direction

The impact of decentral dispatching strategies on the performance of intralogistics transport systems

This thesis focuses on control strategies for intralogistics transport systems. It evaluates how switching from central to decentral dispatching approaches influences the performance of these systems. Many ideas and prototypes for implementing decentral control have been suggested by the scientific community. But usually only the qualitative advantages of this new paradigm are stated. The impact on the performance is not quantified and analyzed. Additionally, decentral control is often confused with distributed algorithms or uses the aggregation of local to global information. In the case of the latter, the technological limitations due to the communication overhead are not considered. The decentral prototypes usually only focus on routing. This paper takes a step back and provides a generic simulation environment which can be used by other researchers to test and compare control strategies in the future. The test environment is used for developing four truly decentral dispatching strategies which work only based on local information. These strategies are compared to a central approach for controlling transportation systems. Input data from two real-world applications is used for a series of simulation experiments with three different layout complexities. Based on the simulation studies neither the central nor the decentral dispatching strategies show a universally superior performance. The results depend on the combination of input data set and layout scenario. The expected efficiency loss for the decentral approaches can be confirmed for stable input patterns. Regardless of the layout complexity the decentral strategies always need more vehicles to reach the performance level of the central control rule when these input characteristics are present. In the case of varying input data and high throughput the decentral strategies outperform the central approach in simple layouts. They require fewer vehicles and less vehicle movement to achieve the central performance. Layout simplicity makes the central dispatching strategy prone to undesired effects. The simple-minded decentral decision rules can achieve a better performance in this kind of environment. But only complex layouts are a relevant benchmark scenario for transferring decentral ideas to real-world applications. In such a scenario the decentral performance deteriorates while the layout-dependent influences on the central strategy become less relevant. This is true for both analyzed input data sets. Consequently, the decentral strategies require at least 36% to 53% more vehicles and 20% to 42% more vehicle movement to achieve the lowest central performance level. Therefore their usage can currently not be justified based on investment and operating costs. The characteristics of decentral systems limit their own performance. The restriction to local information leads to poor dispatching decisions which in return induce self-enforcing inefficiencies. In addition, the application of decentral strategies requires bigger storage location capacity. In several disturbance scenarios the decentral strategies perform fairly well and show their ability to adapt to changed environmental conditions. However, their performance after the disturbance remains in some cases unpredictable and relates to the properties of self-organizing complex systems. A real-world applicability has to be called into question

RE|Fab : How the 10% Investment Tax Credit Can Aid in the Creation of a Prefabricated System for the Rehabilitation of Non-Designated Historic Structures

Historically known as “the Workshop of the World”, Philadelphia was home to numerous industries that served as financial anchors for the neighborhoods surrounding them. However, due to a loss of industry these anchors have become dangerous, attractors of unsavory activity, and impediments to growth and safety. In order to reconnect the frayed social and economic fabrics that exist surrounding these buildings, a balance must be created between the building’s historic significance and the contemporary needs and potentials of the surrounding area. Although, many of these vacant buildings are old enough to be considered historic most are not historically designated. While there are numerous incentives available to ‘preserve’ buildings that are historically designated, it is the non-designated buildings that often offer more contemporary design flexibility. In order to bring these buildings back to life, the quantitative requirements of the 10% Investment Tax Credit (ITC) for the rehabilitation of existing structures will be used as the spring board for the design. In addition, strategies that emphasize rapid, cost effective and flexible retrofit will be emphasized and techniques of prefabrication and rapid deployment will be explored. This thesis project explores how the implementation of a prefabricated, mass customizable, construction system into the rehabilitation of an existing building can help address issues of vacancy within the city. Can the creation of a prefabricated frame and panel system capable of being deployed within a structurally sound existing building begin to restitch the building to the neighborhood and the neighborhood to the city

Designing for Future Building Adaptive Reuse

ii (350 words) Adaptive reuse of existing buildings can play a significant role in mitigating climate change by reusing embodied energy and resources in place and acting as a viable alternative to demolition and landfill. It also offers social benefits by revitalising familiar landmarks and preserving cultural and heritage values. Further, it is important that designers should explicitly consider maximising the adaptive reuse potential of new buildings at the time that they are designed and anticipate their future uses aside from its original use. Reviewing the design principles implemented in the past, this research identifies a knowledge gap pertaining to an absence of clear criteria for future adaptive reuse and the lack of consensus as how to maximise adaptive reuse potential. Thus, this research is an explorative study and retrospectively analyses successful adaptive reuse projects with a view to establishing and testing a multi-criteria decision

Projeto de layouts de armazéns e melhoria dos processos logísticos

Atualmente o ambiente macroeconómico industrial no qual as empresas estão inseridas, é caracterizado pela sua intensa competitividade. O sucesso de uma organização depende não só da sua capacidade de adaptação às exigências do mercado, como também da eficiência das práticas implementadas. Desta forma, o aumento de produtividade nas operações de armazenagem resulta na melhoria dos processos logísticos da empresa, concedendo-lhe vantagem competitiva. O projeto apresentado foi elaborado em contexto industrial, na empresa Amorim Cork Flooring, S.A., na área de logística, mais especificamente no departamento de armazéns. Este projeto ocorreu com a integração num outro projeto já existente na empresa, cujo objetivo era a reestruturação de todo o sistema logístico da empresa. O foco do projeto consistiu na organização dos espaços para armazenagem de LVT e no apoio à implementação de um armazém central para armazenagem de produto acabado, tendo como finalidade a melhoria dos processos de armazenagem. Iniciou-se o estudo com uma contextualização do problema, seguida de um enquadramento teórico dos tópicos relacionados com o tema principal e, por último, a aplicação ao caso de estudo real, envolvendo análise de dados, definição de indicadores de desempenho, criação e avaliação de propostas para soluções alternativas e seleção da melhor proposta. Neste sentido, foram aplicadas diversos métodos, nomeadamente o diagrama de Ishikawa, a Análise ABC e a análise XYZ, um software CAD para o desenho do layout dos armazéns de LVT e ainda metodologias lean, nomeadamente a gestão visual. As propostas apresentadas incluem a criação de localizações e a identificação de algumas delas com etiqueta própria, assim como sistemas e equipamentos para automatização das atividades internas no armazém. Neste momento, algumas dessas propostas encontram-se em fase de análise e outras já em fase de implementação, não tendo, contudo, sido concluídas.Currently, the industrial macroeconomic environment in which companies operate is characterized by its intense competitiveness. The success of an organization depends not only on its ability to adapt to market demand, but also on the efficiency of the implemented practices. In this way, the increase in productivity in warehousing operations results in the improvement of the company's logistical processes, granting it a competitive advantage. The project presented in this report was developed in an industrial context, in the company Amorim Cork Flooring, S.A., in the logistics area, more specifically in the warehouse department. This project occurred with the integration in another project already existing in the company, whose objective was the restructuring of the entire logistics system of the company. The focus of the project consisted of organizing spaces for LVT storage and supporting the implementation of a central warehouse for storing finished products, with the aim of improving storage processes. The study started with a contextualization of the problem, followed by a theoretical framework of topics related to the main theme and finally the application to the real case study, involving data analysis, definition of performance indicators, creation of proposals for alternative solutions and the selection of the best proposal. In this sense, several methods were applied, namely the Ishikawa diagram, ABC Analysis and XYZ Analysis, CAD software for the layout design of the LVT warehouses and also lean methodologies, namely visual management. The proposals presented included the creation of locations and the identification of some of them with their own label, as well as systems and equipment for automating internal activities in the warehouse. At the moment, some of these proposals are under analysis and others are already being implemented, however, they have not yet been concluded.Mestrado em Engenharia e Gestão Industria