Esta dissertação descreve o desenvolvimento de um sistema de planejamento e controle gerencial que utiliza a metodologia PERT/CPM. O objetivo do trabalho foi a criação de um sistema de planejamento voltado ao pequeno e médio usuário que permitisse grande interação deste com o problema. São descritas todas as fases do projeto, desde as análises iniciais do problema e proposta de alternativas para o modelo de representação, até a descrição da implementação. A implementação foi realizada em um computador do tipo APLLE II dando especial atenção ao projeto do diálogo usuário-sistema. / This work describes the development of a planning, management and control system based on the PERT/CPM methodology. The goal was to develop an interactive planning system to be used by the small and middle user. All the project phases are describe, from the problem analysis and alternatives of model representation up to the description of the implementation. The implementation was made in a Apple II computer emphasizing the project of the user - system language.

Esta dissertação descreve o desenvolvimento de um sistema de planejamento e controle gerencial que utiliza a metodologia PERT/CPM. O objetivo do trabalho foi a criação de um sistema de planejamento voltado ao pequeno e médio usuário que permitisse grande interação deste com o problema. São descritas todas as fases do projeto, desde as análises iniciais do problema e proposta de alternativas para o modelo de representação, até a descrição da implementação. A implementação foi realizada em um computador do tipo APLLE II dando especial atenção ao projeto do diálogo usuário-sistema. / This work describes the development of a planning, management and control system based on the PERT/CPM methodology. The goal was to develop an interactive planning system to be used by the small and middle user. All the project phases are describe, from the problem analysis and alternatives of model representation up to the description of the implementation. The implementation was made in a Apple II computer emphasizing the project of the user - system language.

Analysis of the "Automated processing of telephone bills" in a large consulting firm. Use of project management methods: logical framework, analysis of stakeholders, responsibility matrix, milestones chart, PERT analysis.The main objective it to develop the concept, in which it will be better to handle projects in the consulting company in the future. The information for the purposes of this thesis were collected using the method of guided interviews with leading professionals in the company and using the online questionnaire.

Nous proposons de développer des outils d’aide à la décision pour l’ordonnancement de chaînes logistiques. Nous privilégions la coopération entre les différents acteurs de la chaîne notamment la négociation avec les fournisseurs sur les dates d’arrivée des composants, et avec les clients sur les dates de livraisons des produits finis. Nous considérons une chaîne logistique qui consiste en un réseau d’entreprises avec des centres de décisions indépendants. Les produits finis ou semi finis des entreprises d’assemblage sont fabriqués en utilisant des composants ou produits semi finis fournis par les autres entreprises du réseau ou par des fournisseurs externes. On est au niveau opérationnel, chaque entreprise construit son ordonnancement par rapport à ses propres centres de production. Comme la production de produits finis dépend des composants, des négociations sont entamées entre les entreprises concernant les dates d’arrivées des composants (les fenêtres de temps). Une solution globale est obtenue par une approche itérative par décomposition incluant des négociations bilatérales entre les centres de production et de décisions pour définir l’ordonnancement juste à temps minimisant la somme des pénalités. Pour résoudre l’ordonnancement juste à temps local de chaque centre de production nous proposons une méthode approchée basée sur les algorithmes génétiques. Chaque solution est évaluée grâce à un algorithme polynomial basé sur le PERT coût. Un contrôle semi décentralisé est envisagé pour assurer la convergence des négociations. Par ailleurs, nous étudions un ensemble de problèmes concernant l’optimisation des transports dans les chaînes logistiques / We propose new decision methods for coordinating supply chain scheduling. We focus on the cooperation between supply chain partners by means of negotiations about suppliers’ raw materials arrival dates, and customers’ delivery dates of finished. We consider a supply chain, which consists in a network of independant enterprises. The finished products (or sub products) of the assembly enterprise are produced using components and/or sub products supplied by other enterprises or by external suppliers. We are at the scheduling level and each enterprise builds its own schedules associated with its production centers. As an operation can be performed only when the production center has received the necessary components, the schedules are dependent. This induces negotiations between decision centers which is expressed by penalty functions associated with soft and hard release dates and due dates. A global solution is searched by an iterative decomposition approach including alternatively bilateral negotiations between the production decision centers and just in time scheduling, minimizing the local total sum of penalties. To solve each local just-in-time scheduling problem, we propose an approximation approach based on meta-heuristics, which explores the set of solutions, in which a solution is described by the job order on each machine and is evaluated using a “pert cost” algorithm.. A semi-decentralized control is suggested to assume the negotiation convergence. Furthermore, we study some transportation optimization problems in supply chains

In decision analysis, continuous uncertainties (i.e., the volume of oil in a reservoir) must be approximated by discrete distributions for use in decision trees, for example. Many methods of this process, called discretization, have been proposed and used for decades in practice. To the author’s knowledge, few studies of the methods’ accuracies exist, and were of only limited scope. This work presents a broad and systematic analysis of the accuracies of various discretization methods across large sets of distributions. The results indicate the best methods to use for approximating the moments of different types and shapes of distributions. New, more accurate, methods are also presented for a variety of distributional and practical assumptions. This first part of the work assumes perfect knowledge of the continuous distribution, which might not be the case in practice. The distributions are often elicited from subject matter experts, and because of issues such as cognitive biases, may have assessment errors. The second part of this work examines the implications of this error, and shows that differences between some discretization methods’ approximations are negligible under assessment error, whereas other methods’ errors are significantly larger than those because of imperfect assessments. The final part of this work extends the analysis of previous sections to applications to the Project Evaluation and Review Technique (PERT). The accuracies of several PERT formulae for approximating the mean and variance are analyzed, and several new formulae presented. The new formulae provide significant accuracy improvements over existing formulae. / text

No description available.

Many computers and devices such as smart phones, laptops and tablet devices are now equipped with multiple network interfaces, enabling them to use multiple paths to access content over the network. If the resources could be used concurrently, end user experience can be greatly improved. The recent studies in MPTCP suggest that improved reliability, load balancing and mobility are feasible. The thesis presents a new multipath delay based algorithm, MPPERT (Multipath Probabilistic Early response TCP), which provides high throughput and efficient load balancing. In all-PERT environment, MPPERT suffers no packet loss and maintains much smaller queue sizes compared to existing MPTCP, making it suitable for real time data transfer. MP-PERT is suitable for incremental deployment in a heterogeneous environment. It also presents a parametrized approach to tune the amount of traffic shift off the congested path. Multipath approach is benefited from having multiple connections between end hosts. However, it is desired to keep the connection set minimal as increasing number of paths may not always provide significant increase in the performance. Moreover, higher number of paths unnecessarily increase computational requirement. Ideally, we should suppress paths with low throughputs and avoid paths with shared bottlenecks. In case of MPTCP, there is no efficient way to detect a common bottleneck between subflows. MPTCP applies a constraint of best single-path TCP throughput, to ensure fair share at a common bottleneck link. The best path throughput constraint along with traffic shift, from more congested to less congested paths, provide better opportunity for the competing flows to achieve higher throughput. However, the disadvantage is that even if there are no shared links, the same constraint would decrease the overall achievable throughput of a multipath flow. PERT, being a delay based TCP protocol, has continuous information about the state of the queue. This information is valuable in enabling MPPERT to detect subflows sharing a common bottleneck and obtain a smaller set of disjoint subflows. This information can even be used to switch from coupled (a set of subflows having interdependent increase/decrease of congestion windows) to uncoupled (independent increase/decrease of congestion windows) subflows, yielding higher throughput when best single-path TCP constraint is relaxed. The ns-2 simulations support MPPERT as a highly competitive multipath approach, suitable for real time data transfer, which is capable of offering higher throughput and improved reliability.

Saarbrücken, Univ., Diplomarb., 1997.

Dissertação (mestrado) - Universidade Federal de Santa Catarina. Centro Tecnologico. Programa de Pós-Graduação em Engenharia de Produção / Made available in DSpace on 2012-10-16T02:29:04Z (GMT). No. of bitstreams: 0Bitstream added on 2013-07-16T17:11:32Z : No. of bitstreams: 1 80317.pdf: 3394994 bytes, checksum: 85e0ef27e61d8f284102d9bd1e127baf (MD5) / A análise de aceleração de projetos tem por objetivo reduzir a duração total de um projeto ao menor custo possível pela aplicação adicional de recursos apenas nas atividades que proporcionam, como contrapartida, a redução esperada na duração total. Apesar de ser eficiente e bastante conhecida, não vem sendo utilizada em larga escala devido a dificuldade em realizá-la por meio de métodos manuais. No entanto, isto pode ser contornado com a adoção de recursos computacionais adequados. A recente popularização do uso de microcomputadores e a inexistência de software comercial com esta característica levaram ao desenvolvimento do ADP, um programa que efetua a aceleração de projetos através do algoritmo do fluxo para CPM de Ford-Fulkerson e que permite - através de relatórios impressos e de várias opções de alteração de dados - uma rápida análise de sensibilidade quanto aos resultados obtidos. Este trabalho descreve o ambiente de projetos, o modelo de aceleração e as características do programa, através de um exemplo simplificado.

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnologico / Made available in DSpace on 2012-10-16T09:36:32Z (GMT). No. of bitstreams: 0Bitstream added on 2016-01-08T19:34:55Z : No. of bitstreams: 1 99808.pdf: 2319551 bytes, checksum: 3272013c96630e9eae96467aaab06838 (MD5)