Integration of database, simulation and CAD towards assisted design of production systems

Tese de doutoramento em Industrial Engineering and SystemsO Projecto de Sistemas de Produção é o tema desta tese. Actualmente existe pressão acentuada para as tarefas relacionadas com o Projecto de Sistemas de Produção, no sentido de serem desenvolvidas ou reorganizadas de forma rápida e eficiente. O mercado global e o rápido progresso dos processos produtivos a isso obrigam. Neste contexto tão dinâmico, a flexibilidade, modularidade e robustez são propriedades muito relevantes para os sistemas de produção. No que diz respeito ao projecto de sistemas de produção, têm sido usadas três categorias de ferramentas computacionais: Projecto Assistido por Computador, Simulação de Processos e Sistemas de Informação. No entanto, estas ferramentas têm sido usadas com baixos níveis de integração. A ausência de integração de informação entre estas três categorias de ferramentas, e também a ausência de uma abordagem sistémica ao Projecto de Sistemas de Produção têm evidenciado duplicação de trabalho, desperdício de tempo, incoerências, dificuldades de comunicação entre os membros da equipa de projecto e erros na fase de projecto. Nesta tese, as ferramentas de computação para o projecto de sistemas de produção são integradas numa arquitectura de sistema único. Há uma necessidade de coerência de informação entre as diferentes ferramentas, explorando-se formas de lidar com a diversidade de informação e assegurando sistemas de produção válidos e eficientes, extraindo vantagens da referida integração de informação. Esta integração foi implementada em MS Access (sistemas de informação e bases de dados), AutoCAD (projecto de layouts) e WITNESS (simulação). MS Access assegura estrutura aberta para a base de dados, permitindo a especificação completa de sistemas com todas as propriedades estruturais e comportamentais e a integração e troca de informação entre WITNESS e AutoCAD. A simulação auxilia o propósito da análise do comportamento dinâmico e estocástico dos sistemas e o CAD auxilia a tomada de decisão de layout em implementações exequíveis. Iterativamente os resultados das simulações são usados para melhorar o projecto de layout no CAD, e os layouts do CAD são usados para novas experimentações em simulação. Esta abordagem suporta optimização global do sistema de produção, tendo em consideração todos os recursos do sistema, suas restrições e todas as medidas de desempenho do sistema. Uma ferramenta computacional para este objectivo de integração é então discutida e desenvolvida. Tendo em consideração as referidas desvantagens associadas às conhecidas abordagens ao Projecto de Sistemas de Produção, a ferramenta deverá incorporar um elevado nível de automação. De facto, a ferramenta proposta - Integrated Design of Systems (IDS) envolve um amplo conjunto de funções para o desenvolvimento das mais usuais tarefas associadas ao Projecto de Sistemas de Produção, desde o nível conceptual até ao nível da implementação: análise do sistema de produção (Pareto (P-Q), Cluster e análise do fluxo de materiais), geração automática de modelos de simulação, geração de layouts alternativos para instalações e plantas de fábrica, visualização de fluxos de materiais, projecto de sistema de transporte e especificação iterativa de dimensão de buffers. O IDS apresenta diferentes alternativas e providencia informação detalhada sobre medidas de desempenho de sistemas de produção, permitindo a opção pela melhor solução. O IDS proporciona uma exploração mais sistemática do espaço de soluções e quantifica o desempenho de cada alternativa, potenciando-se a obtenção de melhores soluções que as obtidas com abordagens não-integradas. O IDS é aberto, permitindo que diferentes organizações possam utilizar esta ferramenta avançada para o Projecto de Sistemas de Produção, explorando as vantagens da simulação e do CAD e da sua integração. O conceito IDS e as suas funcionalidades foram validadas através da implementação em diferentes projectos, em diversas áreas de aplicação (empresa cimenteira, indústria automóvel, reorganização de chão de fábrica, sistema logístico interno e projecto para CampusThis thesis deals with production systems design. Nowadays, there is a great pressure on production systems design to be developed or reorganised rapidly and efficiently due to the worldwide competitive market and rapid progress in manufacturing processes. In this dynamic context, flexibility, modularity and robustness are desired production system properties. As far as Production Systems Design is concerned, three basic classes of software tools have been used: Computer Aided Design, Process Simulation and Information Systems. However, these software tools have been used with low levels of integration. The absence of data integration within these three classes of software tools, and also the absence of a systemic approach to Production Systems Design have been causing duplication of work, waste of time, incoherencies, difficulties in project team communication, and errors in the design phase. In this thesis, production systems design software tools are integrated into an unified system architecture. There is a need of data coherence between different software tools, exploring ways of dealing with data diversity and assuring valid and efficient production systems, taking advantage of the mentioned data integration. This integration is implemented on MS Access (information systems and databases), AutoCAD (layout design) and WITNESS (simulation). MS Access provides open database structure, allowing integration and data exchange between WITNESS and AutoCAD. Simulation helps on dynamic systems analysis and CAD on static arrangement on a feasible implementation. Iteratively the results from the simulations are used to improve CAD layout design, and CAD layouts are used in new simulation experiments. This approach supports global system optimization that considers all important system resources and system performance measures. A software tool for this integration is then discussed and developed. Taking into consideration the referred disadvantages of known approaches to production systems design phase, the software tool should acknowledge a high automation level. In fact the proposed Integrated Design of Systems tool (IDS) involves a wide set of functions for the most common tasks of production systems design, from conceptual level to implementation level: systems analysis (PQ, cluster and material flow analysis), automatic generation of simulation models, generation of facility and factory layouts alternatives, material flows displaying, transportation system design and iterative buffer size specification. IDS shows several alternatives and provides detailed information on production systems performance measures, enabling to choose the best solution. Solutions achieved using IDS are expected to be better than solutions obtained with nonintegrated approaches. IDS approach is open and accessible, thus enabling different companies to use this advanced production systems design tool, taking advantage of simulation and CAD systems and their integration. IDS concept and functionalities have been validated through the implementation in several different projects, in different application areas (cement factory, automotive industry, re-layout of job-shop layout, internal logistic system and design of a university campus)

Automatic generation of computer models through the integration of production systems design software tools

The design of production and logistic systems is a process of managing both technical and organizational variants in order to identify the best solution for a given system. This is a very well-known industrial engineering issue, where the objectives for designing such a system have been changing over the last decades. Former approaches were concerned about material handling costs only but more recent works include re-layout and product mix costs, together with a great concern on processes – high service levels, optimal scheduling policies, setup times and costs, etc. Nowadays, the rapid technological progress and the associated competitive problems lead to a great need of fast and successful solutions to deal with continuous change (re-design) of the currently used industrial systems. Flexibility, modularity, efficiency and robustness are generally highly desired system properties. For general design of industrial systems, three basic types of software tools are used: Computer Aided Design, Simulation and Information Systems. These tools help on improving the utilization of system resources like equipment, manpower, materials, space, energy, information, etc. Nevertheless these three types of software tools have been used with low levels of integration. This absence of an adequate data connection and integration of outputs cause time delays in the design process, duplication of work and could also be a source of errors. In this work, Production Systems Design software tools integration possibilities are discussed and a unified system architecture solution, implemented on AutoCAD (layout design), Witness (Simulation) and MS-Access (Information Systems) is presented. The aim is to focus on the need of data coherence between different software tools, exploring ways of dealing with data diversity and assuring valid and efficient solutions. MS-Access supports the specification of the system and data exchange between Witness and AutoCAD. Based on the database specification, our application automatically generates simulation programs and also different spatial patterns of project layouts. These tasks are implemented in Visual Basic code. Iteratively the results from the simulations are used to improve AutoCAD layouts and AutoCAD layouts are used in new simulations. The use of our application, in the examples showed in this paper, proved to get quick, valid and efficient solutions.Fundação para a Ciência e Tecnologi

Integrated design of production systems in a lighting manufacturer using CAD and simulation in layout and process optimization

This paper discusses production systems design issues, applied to the production system layout of a manufacturer of lighting fittings and components. In this paper, production systems design software tools – Information Systems, Simulation and Computer Aided Design are integrated, exploring ways of dealing with data diversity and assuring valid and efficient production system layouts, taking advantage of the mentioned data integration. This integration is implemented on Microsoft Access (databases with system knowledge repository), AutoCAD (layout design) and WITNESS (simulation). The software package developed was called IDS (Integrated Design of Systems). This approach can help on global system optimization that considers all important system resources and system performance measures. Solutions are expected to be faster to achieve and better than solutions obtained with non-integrated approaches. IDS approach is open and accessible, thus enabling different companies to use this advanced production systems design tool, taking advantage of simulation and CAD systems and their integration. This application intends to validate the concept and functionalities of the proposed tool, on a real industrial case study.This work has been supported by FCT – Fundação para a Ciência e Tecnologia (algoritmi

Layout and process optimisation: using computer-aided design (CAD) and simulation through an integrated systems design tool

The design of production and logistic systems is a process of managing both technical and organisational variants in order to identify the best solution for a given system. This paper discusses design issues of production systems that are applied to an internal logistic system in the automotive industry. As far as the production systems design (PSD) is concerned, three basic classes of software tools usually pertain: computer-aided design (CAD), process simulation, and information systems. However, these software tools have been used with low levels of integration. Vik et al. (2010b, 2010c) proposed integrating these software resources in production systems and developed an advanced tool called integrated design of systems (IDS). The proposed IDS tool involves a wide set of functions for the most common tasks of PSD, from conceptualisation to implementation, including systems analysis (P-Q, cluster, and material flow analysis), automatic generation of simulation models, generation of alternatives for the layout of facilities and factories, material flows display, transportation system design, and iterative buffer size specification. The IDS approach takes advantage of simulation, CAD systems, and their integration. This paper will demonstrate the concept and functionalities of the proposed tool in a real industrial case study.Fundação para a Ciência e Tecnologi

Wolf outside, dog inside? The genomic make-up of the Czechoslovakian Wolfdog

Background Genomic methods can provide extraordinary tools to explore the genetic background of wild species and domestic breeds, optimize breeding practices, monitor and limit the spread of recessive diseases, and discourage illegal crossings. In this study we analysed a panel of 170k Single Nucleotide Polymorphisms with a combination of multivariate, Bayesian and outlier gene approaches to examine the genome-wide diversity and inbreeding levels in a recent wolf x dog cross-breed, the Czechoslovakian Wolfdog, which is becoming increasingly popular across Europe. Results Pairwise FST values, multivariate and assignment procedures indicated that the Czechoslovakian Wolfdog was significantly differentiated from all the other analysed breeds and also well-distinguished from both parental populations (Carpathian wolves and German Shepherds). Coherently with the low number of founders involved in the breed selection, the individual inbreeding levels calculated from homozygosity regions were relatively high and comparable with those derived from the pedigree data. In contrast, the coefficient of relatedness between individuals estimated from the pedigrees often underestimated the identity-by-descent scores determined using genetic profiles. The timing of the admixture and the effective population size trends estimated from the LD patterns reflected the documented history of the breed. Ancestry reconstruction methods identified more than 300 genes with excess of wolf ancestry compared to random expectations, mainly related to key morphological features, and more than 2000 genes with excess of dog ancestry, playing important roles in lipid metabolism, in the regulation of circadian rhythms, in learning and memory processes, and in sociability, such as the COMT gene, which has been described as a candidate gene for the latter trait in dogs. Conclusions In this study we successfully applied genome-wide procedures to reconstruct the history of the Czechoslovakian Wolfdog, assess individual wolf ancestry proportions and, thanks to the availability of a well-annotated reference genome, identify possible candidate genes for wolf-like and dog-like phenotypic traits typical of this breed, including commonly inherited disorders. Moreover, through the identification of ancestry-informative markers, these genomic approaches could provide tools for forensic applications to unmask illegal crossings with wolves and uncontrolled trades of recent and undeclared wolfdog hybrids

Unravelling the Scientific Debate on How to Address Wolf-Dog Hybridization in Europe

Anthropogenic hybridization is widely perceived as a threat to the conservation of biodiversity. Nevertheless, to date, relevant policy and management interventions are unresolved and highly convoluted. While this is due to the inherent complexity of the issue, we hereby hypothesize that a lack of agreement concerning management goals and approaches, within the scientific community, may explain the lack of social awareness on this phenomenon, and the absence of effective pressure on decision-makers. By focusing on wolf x dog hybridization in Europe, we hereby (a) assess the state of the art of issues on wolf x dog hybridization within the scientific community, (b) assess the conceptual bases for different viewpoints, and (c) provide a conceptual framework aiming at reducing the disagreements. We adopted the Delphi technique, involving a three-round iterative survey addressed to a selected sample of experts who published at Web of Science listed journals, in the last 10 years on wolf x dog hybridization and related topics. Consensus was reached that admixed individuals should always be defined according to their genetic profile, and that a reference threshold for admixture (i.e., q-value in assignment tests) should be formally adopted for their identification. To mitigate hybridization, experts agreed on adopting preventive, proactive and, when concerning small and recovering wolf populations, reactive interventions. Overall, experts' consensus waned as the issues addressed became increasingly practical, including the adoption of lethal removal. We suggest three non-mutually exclusive explanations for this trend: (i) value-laden viewpoints increasingly emerge when addressing practical issues, and are particularly diverging between experts with different disciplinary backgrounds (e.g., ecologists, geneticists); (ii) some experts prefer avoiding the risk of potentially giving carte blanche to wolf opponents to (illegally) remove wolves, based on the wolf x dog hybridization issue; (iii) room for subjective interpretation and opinions result from the paucity of data on the effectiveness of different management interventions. These results have management implications and reveal gaps in the knowledge on a wide spectrum of issues related not only to the management of anthropogenic hybridization, but also to the role of ethical values and real-world management concerns in the scientific debate

Integrationsmöglichkeiten von Software-Werkzeugen für den Entwurf von Fertigungssystemen

V současné době je kladen velký tlak na rychlou a kvalitní tvorbu návrhů projektů výrobních systémů. Pro tyto účely se používá různých softwarových pomůcek pro analýzu, návrh a ověření těchto projektů. Tyto pomůcky se ale většinou používají samostatně nebo s minimální vzájemnou datovou provázaností. Ruční spojování projektových dat vede ke zpomalení v procesu navrhování, duplikační činnosti, případně je i zdrojem chyb. Článek se obecně zabývá tématikou navrhování výrobních projektů, konkrétně integrací jednotlivých softwarových pomůcek do jednoho systému. Jsou zde popsány jednotlivé nástroje a jejich funkce, principy integrace a další možnosti plynoucí z tohoto propojení jako např. generování simulačních modelů z databáze, generování pozic zařízení do výrobního layoutu a jejich optimálního vzájemného uspořádání podle materiálových toků.Obecnie duży nacisk kładziony jest na szybkie i wysokiej jakości projektowanie systemów produkcji. W tym celu stosowane są różne narzędzia softwarowe służące do ich analizy, projektowania i weryfikacji. Jednak w większości przypadków narzędzia te stosowane są samodzielnie i przy niskim poziomie integracji danych. Manualne łączenie danych projektowych wydłuża proces projektowania, powoduje powielanie czynności i stanowi źródło powstawania błędów. Tematyka artykułu związana jest z projektowaniem systemów produkcyjnych, a w szczególności dotyczy połączenia poszczególnych narzędzi softwarowych w jeden system. W pracy opisano poszczególne narzędzia i ich funkcje, zasady ich łączenia oraz wynikające z niego możliwości. Należy do nich przykładowo generowanie modeli symulacyjnych z bazy danych, generowanie pozycji urządzenia w rozmieszczeniu (layout) produkcji oraz ich opty malnego umiejscowienia wobec siebie w zależności od przepływów materiałowych.Nowadays there is a great pressure on production systems design to be done in a short time and more effectively. Moreover, it must support the systems’ flexibility, modularity and robustness. For these purposes several software tools have been used– mainly for project analysis, design and validation. Nevertheless, these tools have been used with a low integration level, including the absence of data coherence. This paper deals with production systems’ design, actually concerning the integration of particular software tools into a unified system. This work identifies different tools, describing their functions and principles of integration. It also addresses the way this integration enabled the automatic generation of simulation programs. Furthermore, it finally discusses ways of making this integration contributing to the automatic generation of different patterns of project layouts.Gegenwärtig besteht großer Druck bei der schnellen und überlegenen Erzeugung von Projekten von Produktionssystemen. Verschiedene Software-Werkzeuge werden für diese Zwecke hauptsächlich zur Analyse, Planung und Kontrolle von Projekten genutzt. Diese Hilfsmittel werden gewöhnlich gesondert oder mit minimalem relativem Datenzusammenhalt genutzt. Dieser Aufsatz konzentriert sich allgemein auf die Thematik des Entwurfs von Produktionssystemen, konkret auf die Integration einzelner Software-Werkzeuge in ein gemeinsames System. Beschrieben werden mannigfaltige Hilfsmittel und ihre Funktionen, Integrationsprinzipien sowie andere Möglichkeiten, die von dieser Integration ausgehen, zum Beispiel automatisches Erzeugen lauffähiger Simulationsmodelle. Die Integration liefert auch die Erzeugung von Stellungen für Anlagen in der Projektskizze

Automatic Generation of Computer Models through the Integration of Production Systems Design Software Tools

The design of production and logistic systems is a process of managing both technical and organizational variants in order to identify the best solution for a given system. This is a very well-known industrial engineering issue, where the objectives for designing such a system have been changing over the last decades. Former approaches were concerned about material handling costs only but more recent works include re-layout and product mix costs, together with a great concern on processes – high service levels, optimal scheduling policies, setup times and costs, etc. Nowadays, the rapid technological progress and the associated competitive problems lead to a great need of fast and successful solutions to deal with continuous change (re-design) of the currently used industrial systems. Flexibility, modularity, efficiency and robustness are generally highly desired system properties. For general design of industrial systems, three basic types of software tools are used: Computer Aided Design, Simulation and Information Systems. These tools help on improving the utilization of system resources like equipment, manpower, materials, space, energy, information, etc. Nevertheless these three types of software tools have been used with low levels of integration. This absence of an adequate data connection and integration of outputs cause time delays in the design process, duplication of work and could also be a source of errors. In this work, Production Systems Design software tools integration possibilities are discussed and a unified system architecture solution, implemented on AutoCAD (layout design), Witness (Simulation) and MS-Access (Information Systems) is presented. The aim is to focus on the need of data coherence between different software tools, exploring ways of dealing with data diversity and assuring valid and efficient solutions. MS-Access supports the specification of the system and data exchange between Witness and AutoCAD. Based on the database specification, our application automatically generates simulation programs and also different spatial patterns of project layouts. These tasks are implemented in Visual Basic code. Iteratively the results from the simulations are used to improve AutoCAD layouts and AutoCAD layouts are used in new simulations. The use of our application, in the examples showed in this paper, proved to get quick, valid and efficient solutions

Simulation in the design of an internal logistic system - Milk run delivering with Kanban control

This paper describes an internal logistic system that uses Milk Runs (MR) also called Logistic Trains (LT) to transport parts in an electronic industry (production of car radios and GPS navigators). The MR design and process analysis are performed using computer simulation as part of a developed tool (IDS) that integrates simulation, database and CAD system together. By using simulation models for research and experimentation, we improve our knowledge about the system, prior to implementation or even changing the real system. The project outcomes, based on the simulation optimization, lead to the reduction of logistic costs and improvement in the availability of material in production lines. These in turn, reduce work in process material (by reducing stock levels and buffers in the production lines) and setting the minimum number of MR and kanban units