28,831 research outputs found

    Warehouse Layout Design for an Automotive Raw Material Supplier

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    The case-study company faced the limited space situation. Thus, the company decided to uninstall their temporary warehouses and locate products in two permanent warehouses. The objective of this research is to design the layouts of the two permanent warehouses so that the spaces can be efficiently used and the total picking distance is low. The past data, Invoices and Stock Data, are used for developing layouts designing processes. This research involves the collecting of Product Size Data to calculate the required space for the products. There are two phases in layout designing process. First phase is the product categories grouping. This phase categorizes product categories into two groups for the two warehouses. The second phase is the layouts designing. In this phase, the layouts of the two warehouses and the locations of the products are designed. According to the company requirements and policies, the Adapted Class-Based Turnover Assignment is adopted in order to design the layouts for the two warehouses. Layouts of the warehouses are designed, analyzed, and evaluated. And, the best layouts give the best trade-off between quantitative results, i.e., the total picking distance and the remaining space, and qualitative results, i.e., the usability and the product suitability. The designed layouts are applied in the case-study company. This research develops a systematic and practical layout designing method which is flexible and can be adopted in other layout designing.The case-study company faces the limited space situation. Thus, the company decides to uninstall their temporary warehouses and re-locate products in two permanent warehouses. The objective of this research is to design the layouts of the two permanent warehouses so that the spaces can be efficiently used and the total picking distance is low. The past data, Invoices and Stock Data, are used for developing layouts designing processes. This research involves the collecting of Product Size Data to calculate the required space for the products. There are two phases in layout designing process. The first phase is the product categories grouping. This phase categorizes product categories into two groups for the two warehouses. The second phase is the layouts designing. In this phase, the layouts of the two warehouses and the locations of the products are designed. According to the company requirements and policies, the Adapted Class-Based Turnover Assignment is adopted in order to design the layouts for the two warehouses. Layouts of the warehouses are designed, analyzed, and evaluated. The best layouts give the best trade-off between quantitative results, i.e., the total picking distance and the remaining space, and qualitative results, i.e., the usability and the product suitability. The designed layouts are applied in the case-study company. This research develops a systematic and practical layout designing method which is flexible and can be adopted in other warehouses

    Designing secure data warehouses by using MDA and QVT

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    The Data Warehouse (DW) design is based on multidimensional (MD) modeling which structures information into facts and dimensions. Due to the confidentiality of the data that it stores, it is crucial to specify security and audit measures from the early stages of design and to enforce them throughout the lifecycle. Moreover, the standard framework for software development, Model Driven Architecture (MDA), allows us to define transformations between models by proposing Query/View/Transformations (QVT). This proposal permits the definition of formal, elegant and unequivocal transformations between Platform Independent Models (PIM) and Platform Specific Models (PSM). This paper introduces a new framework for the design of secure DWs based on MDA and QVT, which covers all the design phases (conceptual, logical and physical) and specifies security measures in all of them. We first define two metamodels with which to represent security and audit measures at the conceptual and logical levels. We then go on to define a transformation between these models through which to obtain the traceability of the security rules from the early stages of development to the final implementation. Finally, in order to show the benefits of our proposal, it is applied to a case study.This work has been partially supported by the METASIGN project (TIN2004-00779) from the Spanish Ministry of Education and Science, of the Regional Government of Valencia, and by the QUASIMODO and MISTICO projects of the Regional Science and Technology Ministry of Castilla-La Mancha (Spain)

    SAMSTARplus: An Automatic Tool for Generating Multi- Dimensional Schemas from an Entity-Relationship Diagram

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    This paper presents a tool that automatically generates multidimensional schemas for data warehouses from OLTP entity-relationship diagrams (ERDs). Based on user’s input parameters, it generates star schemas, snowflake schemas, or a fact constellation schema by taking advantage of only structural information of input ERDs. Hence, SAMSTARplus can help users reduce efforts for designing data warehouses and aids decision making

    Designing data warehouses for geographic OLAP querying by using MDA

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    Data aggregation in Geographic Information Systems (GIS) is a desirable feature, spatial data are integrated in OLAP engines for this purpose. However, the development and operation of those systems is still a complex task due to methodologies followed. There are some ad hoc solutions that deal only with isolated aspects and do not provide developer and analyst with an intuitive, integrated and standard framework for designing all relevant parts. To overcome these problems, we have defined a model driven approach to accomplish Geographic Data Warehouse (GDW) development. Then, we have defined a data model required to implement and query spatial data. Its modeling is defined and implemented by using an extension of UML metamodel and it is also formalized by using OCL language. In addition, the proposal has been verified against a example scenario with sample data sets. For this purpose, we have accomplished a developing tool based on Eclipse platform and MDA standard. The great advantage of this solution is that developers can directly include spatial data at conceptual level, while decision makers can also conceptually make geographic queries without being aware of logical details.This work has been partially supported by the ESPIA project (TIN2007-67078) from the Spanish Ministry of Education and Science and by the QUASIMODO project (PAC08-0157-0668) from the Castilla-La Mancha Ministry of Education and Science (Spain). Octavio Glorio is funded by the University of Alicante under the 11th Latin American grant program

    Precise design of environmental data warehouses

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    People use data warehouses to help them make decisions. For example, public policy decision-makers can improve their decisions by using this technology to analyze the environmental effects of human activity. In production systems, data warehouses provide structures for extracting the knowledge required to optimize systems. Designing data warehouses is a complex task; designers need flexible and precise methods to help them create data warehouses and adapt their analysis criteria to developments in the decision-making process. In this paper, we introduce a flexible method based on UML (Unified Modeling Language). We introduce a UML profile for building multi-dimensional models and for choosing different criteria according to analysis requirements. This profile makes it possible to specify integrity constraints in OCL (Object Constraint Language). We apply our method to the construction of an environmental system for analyzing the use of certain agricultural fertilizers. We integrate various data sources into a multi-dimensional model showing several categories of analysis, and the consistency of data can be checked with OCL constraints

    GenoQuery: a new querying module for functional annotation in a genomic warehouse

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    Motivation: We have to cope with both a deluge of new genome sequences and a huge amount of data produced by high-throughput approaches used to exploit these genomic features. Crossing and comparing such heterogeneous and disparate data will help improving functional annotation of genomes. This requires designing elaborate integration systems such as warehouses for storing and querying these data

    Building an XML document warehouse

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    International audienceData Warehouses and OLAP (On Line Analytical Processing) technologies are dedicated to analyzing structured data issued from organizations' OLTP (On Line Transaction Processing) systems. Furthermore, in order to enhance their decision support systems, these organizations need to explore XML (eXtensible Markup Language) documents as an additional and important source of unstructured data. In this context, this paper addresses the warehousing of document-centric XML documents. More specifically, we propose a two-method approach to build Document Warehouse conceptual schemas. The first method is for the unification of XML document structures; it aims to elaborate a global and generic view for a set of XML documents belonging to the same domain. The second method is for designing multidimensional galaxy schemas for Document Warehouses

    Using Ontologies for the Design of Data Warehouses

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    Obtaining an implementation of a data warehouse is a complex task that forces designers to acquire wide knowledge of the domain, thus requiring a high level of expertise and becoming it a prone-to-fail task. Based on our experience, we have detected a set of situations we have faced up with in real-world projects in which we believe that the use of ontologies will improve several aspects of the design of data warehouses. The aim of this article is to describe several shortcomings of current data warehouse design approaches and discuss the benefit of using ontologies to overcome them. This work is a starting point for discussing the convenience of using ontologies in data warehouse design.Comment: 15 pages, 2 figure

    Chemical industry supply chain optimisation using agent-based modelling

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    In this paper we present an application of Supply Chain Spread Sheet Simulator (SCSS) in a task dealing with chemical industry supply chain redesign and optimisation. SCSS uses principles of Agent-Based Modelling combining 4 types of agents with 3 algorithms to control their behaviour. Location Algorithm is used to place the logistics objects satisfying the demand of customers, Clarke&Wright's Savings Algorithm is applied to plan the routes and Past Stock Movement Simulation is used to control the stock levels. SCSS is developed in MS Excel using programming language Visual Basic for Applications. Its basic functionality is discussed simulating a real task dealing with the redesign of the distribution system for goods coming from chemical industry in the Czech Republic. We test 6 different structures of the distribution system differing in number of located logistics objects ranging from 1 to 6. Based on the outputs of SCSS recalculated to distribution costs we suggest decreasing the number of located warehouses from 6 to 1 estimating almost 33 % distribution costs savings per year
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