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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Motion planning of mobile robot in dynamic environment using potential field and roadmap based planner

Malik, Waqar Ahmad 30 September 2004 (has links)
Mobile robots are increasingly being used to perform tasks in unknown environments. The potential of robots to undertake such tasks lies in their ability to intelligently and efficiently locate and interact with objects in their environment. My research focuses on developing algorithms to plan paths for mobile robots in a partially known environment observed by an overhead camera. The environment consists of dynamic obstacles and targets. A new methodology, Extrapolated Artificial Potential Field, is proposed for real time robot path planning. An algorithm for probabilistic collision detection and avoidance is used to enhance the planner. The aim of the robot is to select avoidance maneuvers to avoid the dynamic obstacles. The navigation of a mobile robot in a real-world dynamic environment is a complex and daunting task. Consider the case of a mobile robot working in an office environment. It has to avoid the static obstacles such as desks, chairs and cupboards and it also has to consider dynamic obstacles such as humans. In the presence of dynamic obstacles, the robot has to predict the motion of the obstacles. Humans inherently have an intuitive motion prediction scheme when planning a path in a crowded environment. A technique has been developed which predicts the possible future positions of obstacles. This technique coupled with the generalized Voronoi diagram enables the robot to safely navigate in a given environment.
42

Parallel-Powered Hybrid Cycle with Superheating “Partially” by Gas Turbine Exhaust

Ghasemi, Milad, Hammodi, Hassan, Moosavi Sigaroodi, Homan January 2014 (has links)
It is of great importance to acquire methods that has a sustainable solution for treatment and disposal of municipal solid waste (MSW). The volumes are constantly increasing and improper waste management, like open dumping and landfilling, causes environmental impacts such as groundwater contamination and greenhouse gas emissions. The rationalization of developing a sustainable solution implies in an improved way of utilizing waste resources as an energy source with highest possible efficiency. MSW incineration is by far the best available way to dispose the waste. One drawback of conventional MSW incineration plants is that when the energy recovery occurs in the steam power cycle configuration, the reachable efficiency is limited due to steam parameters. The corrosive problem limits the temperature of the superheated steam from the boiler which lowers the efficiency of the system. A suitable and relatively cheap option for improving the efficiency of the steam power cycle is the implementation of a hybrid dual-fuel cycle. This paper aims to assess the integration of an MSW incineration with a high quality fuel conversion device, in this case natural gas (NG) combustion cycle, in a hybrid cycle. The aforementioned hybrid dual-fuel configuration combines a gas turbine topping cycle (TC) and a steam turbine bottoming cycle (BC). The TC utilizes the high quality fuel NG, while the BC uses the lower quality fuel, MSW, and reaches a total power output of 50 MW.  Using a high-quality fuel in cogeneration can prove to be beneficial for improving and enhancing the overall plant profitability and efficiency while eliminating the corrosion problems with conventional MSW firing. The need for few interconnections between the different subunits in a parallel-fueled system allows for a wider range of operation modes and leaves room for service modes of the subunit. The hybrid dual-fuel cycle will be assessed for optimal cycle configuration and evaluated to how it compares to the sum of two separate single-fuel plants with optimal cycle configurations. Investigation of such aspects is a very important issue in order to be able to fully promote an implementation of hybrid combined cycle. The work presented herein also concentrates on investigating scenarios that include a full-load and part-load analysis in both condensing and combined heat and power (CHP) mode of operation. Through simulations and evaluation of obtained data, the results strengthens the fact that the electrical efficiency of hybrid configurations increases at least with 2% in condensing mode and 1,5% in CHP mode, comparing it to the sum of two separate single-fuel units of similar scale. The simulations show increased electrical efficiencies when running the BC in part-load and the TC in full load, with a higher NG to MSW ratio. The results also indicated that it is possible to extract more power output from the cycle by operating in CHP mode, due to more energy being utilized from the input fuel.
43

Active transport journey planner methodology

Hu, W. January 2009 (has links)
This research aims to define and develop a methodology to assist an individual traveller to select healthier and more sustainable transport routes and modes among admissible transport options and highlight the trade-offs among multiple objectives in terms of health, economic, social and environmental benefits. It aims to assist an individual traveller with multi-objectives to make more informed decisions in route and mode planning. The objectives in the case study were identified as personal energy expenditure, travel time, travel cost, CO2 emissions and energy resource consumption concerning sustainability. / This research presents procedures for estimating a range of costs and benefits for journeys; procedures for determining the optimal route for an individual’s trip in an urban area based on cost and benefit estimates and preference weights for specific objectives; procedures for undertaking sensitivity analysis for the optimal route; and uses of the cost and benefit estimation and optimal route generation procedures to conduct a case study for a realistic journey in Melbourne. / An active transport journey planner model was developed in MS Excel to allow users to set constraints for most objectives and give their corresponding weightings, respectively. The recommended transport solution (the least total disutility one) and ranking of other options along with their detailed objective-related information are derived. A case study shows that the methodology developed could be applied in selecting more informed transport solutions based on the user’s multi-objective preferences. In addition, transport options incorporating more cycling and walking have the higher probability to deliver healthier and more sustainable solution to users if social, environmental concerns were considered beyond economic issues. Meanwhile, in sensitivity analysis, the tornado diagrams and spiderplots diagrams are used for demonstrating how sensitive each transport option’s disutility is to the weightings of objectives.
44

Contribuições para a coleta e a análise de indicadores de planejamento e controle da produção na construção civil / Contributions for data colection and analysis of indicators of production planning and control in construction

Bortolazza, Rodrigo Cremonesi January 2006 (has links)
Nos últimos anos, muitas empresas de construção civil têm buscado melhorar seus sistemas de Planejamento e Controle da Produção (PCP) como uma das formas de melhorar o desempenho de empreendimentos em termos de prazo e custo, além dos constantes objetivos de aumentar a qualidade e a produtividade. Um marco importante no desenvolvimento de sistemas de PCP para esse setor foi a introdução do sistema Last Planner de controle da produção, concebido com base em modelos e teorias desenvolvidos para a Engenharia Industrial, a partir de meados da década de 90. Esse sistema tem sido refinado em diversos estudos ao redor do mundo, grande parte deles baseados em uma análise qualitativa dos dados gerados. De fato, as pesquisas relacionadas à implementação de sistemas de PCP desenvolvidas no Programa de Pós-graduação em Engenharia Civil da UFRGS nos últimos anos também foram fortemente baseadas no Last Planner. O objetivo geral dessa dissertação consiste em propor contribuições para a coleta e a análise de dados que permitam avaliar o impacto de sistemas de PCP no desempenho de empreendimentos de construção civil, assim como identificar algumas dificuldades de implementação. Foi criada uma base de dados com as medidas de desempenho coletadas em empresas, em pesquisas anteriores, e também com dados inseridos em um sistema de indicadores para benchmarking de empresas do setor. Foram realizadas diversas análises, principalmente dos indicadores PPC e causas do não cumprimento das tarefas, utilizando a análise de regressão múltipla. Entre as principais conclusões, o estudo apontou formas de melhorar a coleta de dados, incluindo a utilização de mecanismos pró-ativos para evitar o acúmulo de valores faltantes e dados espúrios. Além disso, sugeriu-se a formação de um banco de dados único para cada empresa para possibilitar o melhor aproveitamento dos dados, uma vez que algumas medidas são coletadas e acabam descartadas sem uma análise aprofundada. Quanto às dificuldades de implementação do PCP, destacaram-se as falhas na análise das causas do não cumprimento dos pacotes de trabalho na etapa de curto prazo e a implementação parcial do planejamento de médio prazo, devido à desconsideração da análise sistemática de restrições. / In recent years, several construction companies have attempted to improve their production planning and control systems in order to improve project performance in terms of time and costs, besides increasing quality and productivity. An important reference in the development of production planning and control systems in this sector has been the introduction of the Last Planner System, conceived from models and theories developed in industrial engineering, since the mid Nineties. This system has been refined in several research studies around the world, most of them based on a qualitative data analysis. In fact, the research studies concerned with production planning and control carried out at the Postgraduate Program in Civil Engineering at UFRGS is recent years have been strongly based on the Last Planner System. The main objective of this dissertation is to make contributions for data collection and analysis for assessing the impact of production planning and control systems in the performance of construction projects, as well as identify some implementation difficulties. A database was built with some measures collected in construction projects in previous research studies, as well as with data from a performance measurement system for benchmarking in this sector. Several analyses were carried out in this data base, mostly based on two measures, the percentage of plan completed (PPC) and the causes for the non completion of work packages, using multivariate regression analysis. Among the main conclusions, this study pointed out ways of improving data collection, including the use of pro-active mechanisms for avoiding the growth of missing values and outliers. Furthermore, it suggests the construction of a single database in each company, enabling the proper use of the data available, since some of the measures are collected but are further discarded without an in-depth analysis. Regarding the difficulties in the implementation of production planning and control, some failures during the analysis of the causes for the non-completion of work packages in short term planning and the incomplete implementation of look-ahead planning, due to the ineffectiveness of constraints analysis, were pointed out.
45

Avaliação do impacto do Sistema Last Planner no desempenho de empreendimentos da construção civil

Moura, Camile Borges January 2008 (has links)
Diversos esforços têm sido dirigidos à melhoria do setor da construção civil no mundo inteiro, podendo ser destacado como um dos principais focos o processo de planejamento e controle da produção (PCP). Este processo tem grande impacto no desempenho dos empreendimentos de construção, em relação aos seus custos, prazos, qualidade e segurança. Uma das principais iniciativas realizadas para a melhoria do PCP foi o desenvolvimento e disseminação do Sistema Last Planner de Controle da Produção (LPS). Esse sistema vem sendo aplicado em diversos países desde meados da década de 1990. O principal indicador do LPS é o Percentual de Planos Concluídos (PPC), que mede a eficácia do planejamento. Contrastando com o elevado número de estudos qualitativos realizados sobre a implementação do LPS, poucas análises quantitativas foram realizadas sobre o impacto de sua implementação e os fatores que afetam a sua eficácia. A partir da construção de uma grande base de dados de empreendimentos, o presente trabalho buscou avaliar o impacto da eficácia de sistemas de PCP, baseados no LPS, no desempenho de empreendimentos da construção civil quanto ao custo e ao prazo. Buscou avaliar também influência de práticas de gestão da produção na construção civil na eficácia destes sistemas de PCP. A base de dados utilizada contém indicadores de PPC, desvio de custo, desvio de prazo, boas práticas de PCP e boas práticas de canteiros de obras. Através da técnica de regressão múltipla foram realizadas diversas análises. Como principais conclusões apontam-se algumas evidências sobre a forma como o PCP influencia o desempenho dos empreendimentos e a importância das boas práticas de PCP e de canteiros de obras na eficácia do planejamento. Apesar de as análises apresentarem níveis de correlação relativamente baixos, devido a algumas limitações dos dados disponíveis, observou-se uma forte consistência nos modelos de regressão desenvolvidos. / Several efforts for improving the construction sector have been made worldwide, and one of the main focus has been the production planning and control process This process has a large impact on the performance of construction projects, in terms of cost, time, quality and safety. One of the main initiatives for improving the planning and control process has been the development and dissemination of the Last Planner System of Production Control (LPS). This system has been used in many different countries since the mid Nineties. The main performance indicator of the LPS is the Percentage of Plans Completed (PPC), which measures planning effectiveness. In contrast with the large number of qualitative studies on the implementation of LPS, very few quantitative analyses have been undertaken on the impact of its implementation and on the factors that affect its effectiveness. Based on the construction of a large project database, this research study aims to assess the impact of LPS based production planning and control systems on the performance of construction projects in terms of cost and time. This investigation has also analysed the impact of a set of production management practices on the effectiveness of those planning systems. The database contains the following indicators: PPC, cost deviation, time deviation, good production planning and control practices, and good site management practices. Several analyses were carried out using regression analysis techniques. As main conclusions, the study provided some evidences on the way production planning and control influences project performance, and the importance of good production planning and control practices, and site management practices on the effectiveness of planning and control. Despite the fact that some of the analyses indicated a fairly low correlation index, due to some limitations on the data available, the regression models produced were very consistent.
46

Contribuições para a coleta e a análise de indicadores de planejamento e controle da produção na construção civil / Contributions for data colection and analysis of indicators of production planning and control in construction

Bortolazza, Rodrigo Cremonesi January 2006 (has links)
Nos últimos anos, muitas empresas de construção civil têm buscado melhorar seus sistemas de Planejamento e Controle da Produção (PCP) como uma das formas de melhorar o desempenho de empreendimentos em termos de prazo e custo, além dos constantes objetivos de aumentar a qualidade e a produtividade. Um marco importante no desenvolvimento de sistemas de PCP para esse setor foi a introdução do sistema Last Planner de controle da produção, concebido com base em modelos e teorias desenvolvidos para a Engenharia Industrial, a partir de meados da década de 90. Esse sistema tem sido refinado em diversos estudos ao redor do mundo, grande parte deles baseados em uma análise qualitativa dos dados gerados. De fato, as pesquisas relacionadas à implementação de sistemas de PCP desenvolvidas no Programa de Pós-graduação em Engenharia Civil da UFRGS nos últimos anos também foram fortemente baseadas no Last Planner. O objetivo geral dessa dissertação consiste em propor contribuições para a coleta e a análise de dados que permitam avaliar o impacto de sistemas de PCP no desempenho de empreendimentos de construção civil, assim como identificar algumas dificuldades de implementação. Foi criada uma base de dados com as medidas de desempenho coletadas em empresas, em pesquisas anteriores, e também com dados inseridos em um sistema de indicadores para benchmarking de empresas do setor. Foram realizadas diversas análises, principalmente dos indicadores PPC e causas do não cumprimento das tarefas, utilizando a análise de regressão múltipla. Entre as principais conclusões, o estudo apontou formas de melhorar a coleta de dados, incluindo a utilização de mecanismos pró-ativos para evitar o acúmulo de valores faltantes e dados espúrios. Além disso, sugeriu-se a formação de um banco de dados único para cada empresa para possibilitar o melhor aproveitamento dos dados, uma vez que algumas medidas são coletadas e acabam descartadas sem uma análise aprofundada. Quanto às dificuldades de implementação do PCP, destacaram-se as falhas na análise das causas do não cumprimento dos pacotes de trabalho na etapa de curto prazo e a implementação parcial do planejamento de médio prazo, devido à desconsideração da análise sistemática de restrições. / In recent years, several construction companies have attempted to improve their production planning and control systems in order to improve project performance in terms of time and costs, besides increasing quality and productivity. An important reference in the development of production planning and control systems in this sector has been the introduction of the Last Planner System, conceived from models and theories developed in industrial engineering, since the mid Nineties. This system has been refined in several research studies around the world, most of them based on a qualitative data analysis. In fact, the research studies concerned with production planning and control carried out at the Postgraduate Program in Civil Engineering at UFRGS is recent years have been strongly based on the Last Planner System. The main objective of this dissertation is to make contributions for data collection and analysis for assessing the impact of production planning and control systems in the performance of construction projects, as well as identify some implementation difficulties. A database was built with some measures collected in construction projects in previous research studies, as well as with data from a performance measurement system for benchmarking in this sector. Several analyses were carried out in this data base, mostly based on two measures, the percentage of plan completed (PPC) and the causes for the non completion of work packages, using multivariate regression analysis. Among the main conclusions, this study pointed out ways of improving data collection, including the use of pro-active mechanisms for avoiding the growth of missing values and outliers. Furthermore, it suggests the construction of a single database in each company, enabling the proper use of the data available, since some of the measures are collected but are further discarded without an in-depth analysis. Regarding the difficulties in the implementation of production planning and control, some failures during the analysis of the causes for the non-completion of work packages in short term planning and the incomplete implementation of look-ahead planning, due to the ineffectiveness of constraints analysis, were pointed out.
47

Avaliação do impacto do Sistema Last Planner no desempenho de empreendimentos da construção civil

Moura, Camile Borges January 2008 (has links)
Diversos esforços têm sido dirigidos à melhoria do setor da construção civil no mundo inteiro, podendo ser destacado como um dos principais focos o processo de planejamento e controle da produção (PCP). Este processo tem grande impacto no desempenho dos empreendimentos de construção, em relação aos seus custos, prazos, qualidade e segurança. Uma das principais iniciativas realizadas para a melhoria do PCP foi o desenvolvimento e disseminação do Sistema Last Planner de Controle da Produção (LPS). Esse sistema vem sendo aplicado em diversos países desde meados da década de 1990. O principal indicador do LPS é o Percentual de Planos Concluídos (PPC), que mede a eficácia do planejamento. Contrastando com o elevado número de estudos qualitativos realizados sobre a implementação do LPS, poucas análises quantitativas foram realizadas sobre o impacto de sua implementação e os fatores que afetam a sua eficácia. A partir da construção de uma grande base de dados de empreendimentos, o presente trabalho buscou avaliar o impacto da eficácia de sistemas de PCP, baseados no LPS, no desempenho de empreendimentos da construção civil quanto ao custo e ao prazo. Buscou avaliar também influência de práticas de gestão da produção na construção civil na eficácia destes sistemas de PCP. A base de dados utilizada contém indicadores de PPC, desvio de custo, desvio de prazo, boas práticas de PCP e boas práticas de canteiros de obras. Através da técnica de regressão múltipla foram realizadas diversas análises. Como principais conclusões apontam-se algumas evidências sobre a forma como o PCP influencia o desempenho dos empreendimentos e a importância das boas práticas de PCP e de canteiros de obras na eficácia do planejamento. Apesar de as análises apresentarem níveis de correlação relativamente baixos, devido a algumas limitações dos dados disponíveis, observou-se uma forte consistência nos modelos de regressão desenvolvidos. / Several efforts for improving the construction sector have been made worldwide, and one of the main focus has been the production planning and control process This process has a large impact on the performance of construction projects, in terms of cost, time, quality and safety. One of the main initiatives for improving the planning and control process has been the development and dissemination of the Last Planner System of Production Control (LPS). This system has been used in many different countries since the mid Nineties. The main performance indicator of the LPS is the Percentage of Plans Completed (PPC), which measures planning effectiveness. In contrast with the large number of qualitative studies on the implementation of LPS, very few quantitative analyses have been undertaken on the impact of its implementation and on the factors that affect its effectiveness. Based on the construction of a large project database, this research study aims to assess the impact of LPS based production planning and control systems on the performance of construction projects in terms of cost and time. This investigation has also analysed the impact of a set of production management practices on the effectiveness of those planning systems. The database contains the following indicators: PPC, cost deviation, time deviation, good production planning and control practices, and good site management practices. Several analyses were carried out using regression analysis techniques. As main conclusions, the study provided some evidences on the way production planning and control influences project performance, and the importance of good production planning and control practices, and site management practices on the effectiveness of planning and control. Despite the fact that some of the analyses indicated a fairly low correlation index, due to some limitations on the data available, the regression models produced were very consistent.
48

Calcul d'itinéraire multicritère en transport multimodal / Multicriteria trip planning in multimodal transportation networks

Iglesias, Alexandre 12 October 2017 (has links)
Les travaux effectués dans cette thèse industrielle concernent l'amélioration du calculateur d'itinéraire de Cityway, société spécialisée dans les technologies de l’information appliquées à la mobilité.Nous avons d'abord établi un état de l'art exhaustif, accompagné d'une mise en perspective de l'existant Cityway avec celui-ci. Cela nous a permis d'aider l'entreprise à prendre du recul sur son produit et de justifier les axes de recherche choisis pour nos travaux.Nous nous sommes ensuite intéressés à l'aspect multicritère du problème. En effet, le calculateur, basé sur l'algorithme de Dijkstra, permet de trouver des trajets minimisant une somme pondérée de critères. Nous avons développé un algorithme multilabel permettant de conserver et étendre plusieurs labels au même nœud. Malgré une légère augmentation des temps de calculs, des résultats satisfaisants ont été obtenus dans une application bicritère de ce nouvel algorithme.Nous avons également travaillé sur la génération et la sélection de trajets alternatifs. La génération s'appuie sur les algorithmes monolabel ou multilabel. La sélection s'appuie quant à elle sur la définition d'une distance entre les solutions et des méthodes de regroupement.Enfin, nous nous sommes intéressés à l'optimisation du calcul du critère lexicographique de durée minimale dans le cas bicritère. Pour qu'un trajet soit intéressant, il faut qu'il soit optimal sur les critères usuels, mais aussi qu'il dure le moins longtemps possible. L'utilisation de certaines propriétés sur ce critère permet de réduire des temps de calcul initialement trop longs. / The work carried out in this industrial PhD aims at improving the route planner of Cityway, a company specialized in information technologies applied to mobility. We first established an exhaustive state of the art, and compared it to the existing Cityway product. This allowed us to help the company take a step back from its urgent needs, and justify the research guidelines chosen for our work.We then looked at the multi-criteria aspect of the problem. Indeed, the trip planner, based on the Dijkstra algorithm, makes it possible to find paths minimizing a weighted sum of criteria. We have developed a multilabel algorithm to maintain and extend multiple labels at the same node. Despite a slight increase in computation time, satisfactory results were obtained in a bicriteria application of this new algorithm.We also worked on the generation and selection of alternative routes. The generation algorithm relies on the existing monolabel or newly developed multilabel algorithms. The selection algorithm is based on the definition of a distance between trips and adaptations of existing clustering algorithms to this specific case.Finally, we were interested in what we called the lexicographic criterion. For a trip to be interesting, it must be optimal on the usual criterion of earliest arrival, and, for trips arriving at the same time, on the latest departure criterion. The use of certain properties on this criterion makes it possible to reduce computation times on the bicriteria case.
49

Availapp : Availapp och andra semesterplanerare

Försth, Sebastian January 2017 (has links)
The aim of this study has been to create and compare different holiday planners. The comparison takes place between availapp, Excel spreadsheets and absence. Availapp is a tailor-made vacation planning application for CGI Sundsvall / Härnösand that is fully scalable with mobile and desktops devices. The applikation automatically retrieves personal information from windowsAD at first login. The web application also takes into account social ethical aspects where we use encryption to ensure that information does not reach the wrong people. Also taking into account with PUL and GDPR for storing user information. Excel spreadsheets is CGI's current vacation planner consisting of an excel sheet with macron to ease the vacation planning. Absence is a commercial holiday planner aimed at companies to replace excel vacation planners. The comparison between availapp, excel spreadsheets and absence is evaluated according to a few key criteria, which is access, readability, navigation, functionality and startup of applications. The result is then compiled in a table to get an easy overview of the criteria for each application. After the compilation, it is found that availapp is the most suitable holiday planner according to the chosen criteria. / Målet med denna undersökning har varit att skapa och jämföra olika semesterplanerare. Jämförelsen sker mellan availapp, excelark och absence. Availapp är en skräddarsydd semesterplaneringsapplikation för CGI sundsvall/härnösand som är helt skalbar med mobil och skrivbord samt automatiskt hämtar personinformation från windowsAD vid första inloggning. Webbapplikationen tar även hänsyn till samhällsetiska aspekter där vi använder oss av kryptering för att säkerställa att information inte kommer till fel personer. Vi håller oss även till PUL och GDPR för lagring av användarinformation. Excelarket är CGI’s nuvarande semesterplanerare som består av ett excelark med macron för att underlätta semesterplaneringen. Absence är en kommersiell semesterplanerare som riktar sig till företag för att ersätta excel semesterplanerare. Jämförelsen mellan availapp, excelarket och absence utvärderas efter ett par nyckelkriterier vilket är åtkomst, läsbarhet, navigering, funktionalitet och uppstart av applikationerna. Resultatet är sedan sammanställt i en tabell för att få en lätt översikt över vilka kriterier varje applikation klara. Efter sammanställningen konstateras det att availapp är den mest lämpade semesterplaneraren efter dom valda kriterierna.
50

Contribuições para a coleta e a análise de indicadores de planejamento e controle da produção na construção civil / Contributions for data colection and analysis of indicators of production planning and control in construction

Bortolazza, Rodrigo Cremonesi January 2006 (has links)
Nos últimos anos, muitas empresas de construção civil têm buscado melhorar seus sistemas de Planejamento e Controle da Produção (PCP) como uma das formas de melhorar o desempenho de empreendimentos em termos de prazo e custo, além dos constantes objetivos de aumentar a qualidade e a produtividade. Um marco importante no desenvolvimento de sistemas de PCP para esse setor foi a introdução do sistema Last Planner de controle da produção, concebido com base em modelos e teorias desenvolvidos para a Engenharia Industrial, a partir de meados da década de 90. Esse sistema tem sido refinado em diversos estudos ao redor do mundo, grande parte deles baseados em uma análise qualitativa dos dados gerados. De fato, as pesquisas relacionadas à implementação de sistemas de PCP desenvolvidas no Programa de Pós-graduação em Engenharia Civil da UFRGS nos últimos anos também foram fortemente baseadas no Last Planner. O objetivo geral dessa dissertação consiste em propor contribuições para a coleta e a análise de dados que permitam avaliar o impacto de sistemas de PCP no desempenho de empreendimentos de construção civil, assim como identificar algumas dificuldades de implementação. Foi criada uma base de dados com as medidas de desempenho coletadas em empresas, em pesquisas anteriores, e também com dados inseridos em um sistema de indicadores para benchmarking de empresas do setor. Foram realizadas diversas análises, principalmente dos indicadores PPC e causas do não cumprimento das tarefas, utilizando a análise de regressão múltipla. Entre as principais conclusões, o estudo apontou formas de melhorar a coleta de dados, incluindo a utilização de mecanismos pró-ativos para evitar o acúmulo de valores faltantes e dados espúrios. Além disso, sugeriu-se a formação de um banco de dados único para cada empresa para possibilitar o melhor aproveitamento dos dados, uma vez que algumas medidas são coletadas e acabam descartadas sem uma análise aprofundada. Quanto às dificuldades de implementação do PCP, destacaram-se as falhas na análise das causas do não cumprimento dos pacotes de trabalho na etapa de curto prazo e a implementação parcial do planejamento de médio prazo, devido à desconsideração da análise sistemática de restrições. / In recent years, several construction companies have attempted to improve their production planning and control systems in order to improve project performance in terms of time and costs, besides increasing quality and productivity. An important reference in the development of production planning and control systems in this sector has been the introduction of the Last Planner System, conceived from models and theories developed in industrial engineering, since the mid Nineties. This system has been refined in several research studies around the world, most of them based on a qualitative data analysis. In fact, the research studies concerned with production planning and control carried out at the Postgraduate Program in Civil Engineering at UFRGS is recent years have been strongly based on the Last Planner System. The main objective of this dissertation is to make contributions for data collection and analysis for assessing the impact of production planning and control systems in the performance of construction projects, as well as identify some implementation difficulties. A database was built with some measures collected in construction projects in previous research studies, as well as with data from a performance measurement system for benchmarking in this sector. Several analyses were carried out in this data base, mostly based on two measures, the percentage of plan completed (PPC) and the causes for the non completion of work packages, using multivariate regression analysis. Among the main conclusions, this study pointed out ways of improving data collection, including the use of pro-active mechanisms for avoiding the growth of missing values and outliers. Furthermore, it suggests the construction of a single database in each company, enabling the proper use of the data available, since some of the measures are collected but are further discarded without an in-depth analysis. Regarding the difficulties in the implementation of production planning and control, some failures during the analysis of the causes for the non-completion of work packages in short term planning and the incomplete implementation of look-ahead planning, due to the ineffectiveness of constraints analysis, were pointed out.

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