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This dissertation extends the work done on single component maintenance planning to a multi-component series system. An attempt is made to develop a function which represents the expected cost rate (cost per unit time) of any maintenance plan. Three increasingly complex cases are considered. The first and simplest case assumes that the component is restored to an “as good as new” condition after a maintenance operation. The second case assumes that an occasional imperfect maintenance Operation may occur. During this period of time, the failure rate of the component is higher. Hence, the likelihood of a failure is greater until the component is properly maintained in a subsequent maintenance operation. The final case assumes that there is some deterioration in the component behavior even after a maintenance operation. Therefore, it is necessary to replace the system at some point in time. Models for all three cases are developed. Based on these models, cost rate functions are constructed. The cost rate functions reflect the cost rates of maintaining a component at a particular time. In addition, the savings obtained through the simultaneous maintenance of components is also accounted for in the cost rate functions. A series of approximations are made in order to make the cost rate functions mathematically tractable. Finally, an algorithmic procedure for optimizing the cost rate functions for all three cases is given. / Ph. D.

A model is developed for use by logistics planners in determining period by period maintenance requirements for repairable item populations. The model generates maintenance requirements with respect to manpower and facility requirements and spare parts requirements. The model is capable of capturing nonsteady-state failure behavior of populations of repairable items. Each item within the population is broken down into one or more families of components and subcomponents that can have different failure/repair characteristics. Probability of component failure may be generally distributed. A specific data requirement for the model is established. The model is structured to allow the user to conduct various"what if gaming" through an iterative procedure on a personal computer. This research document includes a literature review that establishes a history of logistics modeling. The literature review provides impetus to the proposed research by defining a need for a transient state model for maintenance requirements planning. The model is validated by a case study involving the generation of maintenance requirements for a case population. / Master of Science

Web applications are subject to intense market forces, fast delivery and rapid requirement and code change. These are the factors that make maintainability a significant concern in any and especially web application development. In this report we develop a functional equivalent prototype from an existing Angular app, using ReactJs and afterward compare their maintainability as defined by ISO/IEC 25010. The maintainability comparison is made by calculating maintainability index for each of the applications using Plato analysis tool. The results do not show a significant difference in the calculated value of the final products. Source code analysis shows that changes in data flow need more modification in the Angular app, but with the objective oriented approach provided by Angular, we can have smaller chunks of code and thus higher maintainability per file and respectively a better average value. We conclude that regarding the lack of research and models in this area, MI is a consistent measurement model and Plato is a suitable tool for analysis. Though maintainability is highly bounded to the implementation, functionalities which are provided by the Angular framework as a bundle is more appropriate for large enterprises and complex products where React works better for smaller products.

This thesis work is mainly focused on the processes involved in manufacturing of aircraft engine components. The processes are especially about welding and welding methods. The basics of welding and the thesis support has been taken from the GKN Aerospace Sweden AB, a global aerospace product supplier.  The basic objective of this thesis work is to improve the usability of an automation system which is developed for evaluating the weldability of a part. A long run maintainability aspect of this automation system has been considered. The thesis work addresses the problems arising during the usage of a computerised automated system such as process transparency, recognisability, details traceability and other maintenance aspects such as maintainability and upgradability of the system in the course of time. The action research methodology has been used to address these problems.  Different approaches have been tried to finding the solution to those problems. A rule based manufacturability analysis system has been attempted to analyse the weldability of a component in terms of different welding technics. The software “Howtomation” has been used to improve the transparency of this analysis system. User recognisability and details tractability have been taken into account during the usage of a ruled based analysis system. The system attributes such as maintainability, upgradability, adaptiveness to modern welding methods has been addressed. The system suitability for large scale analysis has been considered.

In this thesis we address a long-term maintainability problem in Haskell type class system. In particular we study a possibility of backward-compatible changes in existing class hierarchies. In the first part of the thesis we give a brief overview of the language. The following part summarizes current proposed solutions to the problem and analyzes their properties. Based on this analysis we derive our own language extension proposal. In the penultimate chapter we present several possible applications of the language extension and compare the extension to other solutions. As a part of the thesis we also give a proof-of-concept implementation of the extension for the GHC compiler, which is briefly described in the last part of this thesis. Powered by TCPDF (www.tcpdf.org)

La siguiente propuesta de implementación está formada por tres capítulos en el primero se está considerando el marco teórico investigado de fuentes con revistas indexadas y respaldado por autores especialistas en los temas de confiabilidad, mantenibilidad definición, evolución, técnica, aplicación y tipos de mantenimiento. En el segundo capítulo la situación y diagnostico actual de la empresa, identificación del activo más relevante y el impacto económico que genera. En el tercer capítulo se muestra la propuesta de la implementación con respecto al diagnóstico que se realizó en los capítulos anteriores. En el cuarto capítulo se muestra la simulación del proceso actual del activo, así como la aplicación de la metodología del RCM, en el cual podemos evaluar la viabilidad de dicha implementación. Finalmente, las conclusiones y recomendaciones. / The following implementation proposal consists of three chapters. In the first one is considering the theoretical framework researched from sources with indexes journals and supported by specialist authors in terms of reliability, maintainability, definition, evolution, technique, application and types of maintenance. The second chapter is about the situation and current diagnosis of the company, identification of the most relevant asset and the economic impact it generates. The third chapter shows the proposal of the implementation with respect to the diagnosis that was made in the previous chapter. The fourth chapter shows the simulation of the current asset process, as well as the application of the RCM methodology, in which we can evaluate the feasibility of such implementation. Finally, the conclusions and recommendations. / Tesis

A falta de integração entre áreas de conhecimento pode gerar efeitos negativos no processo de projeto em uma construtora-incorporadora. Em muitos casos, o projeto do produto é elaborado pela incorporadora sem qualquer participação da área responsável pela produção e de outras áreas da construtora. O trabalho apresenta uma análise sobre a gestão de projetos na construção de edifícios, valorizando a participação da engenharia de produção nessa fase, apoiando-se nos conceitos de Projeto Simultâneo, e propõe diretrizes para sua aplicação na construtora-incorporadora Cyrela, com enfoque na construtibilidade e manutenibilidade. Para desenvolver a pesquisa foi realizada uma revisão bibliográfica sobre as características da gestão de projetos, da Engenharia de Produção na construção de edifícios, e sobre a Engenharia Simultânea no desenvolvimento de produtos com comparativo de modelos de indústrias seriadas para a construção civil, incluindo a interação entre os agentes do processo. Como resultados são apresentados: uma análise da interação entre os agentes do processo; a ligação entre pessoas, processos e tecnologia; os conceitos de construtibilidade, manutenibilidade e retroalimentação na interface com projetos. São igualmente feitas análises das tendências de modernização na gestão dos projetos por meio da modelagem da informação da construção e, apoiado em estudo de caso, são apresentadas as experiências do Projeto Simultâneo aplicadas na Cyrela. Por fim, são apresentadas as diretrizes para participação da Engenharia de Produção da Construtora e Incorporadora Cyrela no Projeto Simultâneo, sendo essa a principal contribuição do trabalho. Embora suas contribuições possam servir de referência para demais empresas do setor, essa pesquisa foi desenvolvida para aplicações práticas da Cyrela, construtora-incorporadora que atua na construção de edifícios em todas as regiões do Brasil. / The lack of integration between knowledge areas can generate negative effects in the design process in a construction-real estate developer. In many cases, the product design is prepared by the real estate developer without any involvement of the area responsible for production and other areas of construction. This thesis presents an analysis of the project management in building construction, valuing the participation of engineering production in this stage, basing on the concepts of Concurrent Design and proposes guidelines for its application at Cyrela constructionreal estate developer company, focusing on constructability and maintainability. To develop the research was performed a literature review about the characteristics of Project Management, Production Engineering in building construction, and the Concurrent Engineering in the development of products with comparative serial industries models for the construction industry, including interaction between agents of the process. As results are presented: an analysis of the interaction between the agents of the process; a link between people, processes and technology; the concepts of constructability, maintainability and feedback on interface with projects. Modernization trends in project management are analyzed also through building information modeling and, through case study, are presented the Concurrent Design experiences applied at Cyrela. Finally are presented the guidelines to the participation of the Production Engineering of Cyrela construction-real estate developer on Concurrent Design, being the main contribution of this thesis. Although the contributions may serve as a reference for other companies in the sector, this research was developed for practical applications at Cyrela, constructionreal estate developer that acts in the construction of buildings in all regions of Brazil.

Tse Yee Kit. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 55-58). / Abstracts in English and Chinese. / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Geometric Process and Maintenance Problem --- p.1 / Chapter 1.2 --- Warranty Problem --- p.5 / Chapter 1.3 --- An Outline of the Thesis --- p.8 / Chapter Chapter 2 --- Multistate Deteriorative System / Chapter 2.1 --- The Multistate Model --- p.10 / Chapter 2.2 --- Long-run Average Cost Per Unit Time --- p.15 / Chapter 2.3 --- The Optimal Policy N* --- p.18 / Chapter 2.4 --- The Monotonicity of the Optimal Policy --- p.21 / Chapter Chapter 3 --- Extended Warranty Model / Chapter 3.1 --- The Extended Warranty Model --- p.30 / Chapter 3.2 --- "The Expected Discounted Cost Over the Lifetime Cycle [0,T]" --- p.34 / Chapter 3.2.1 --- Consumer's Discounted Cost --- p.34 / Chapter 3.2.2 --- Manufacturer's Discounted Cost --- p.37 / Chapter 3.3 --- The Exponential Distribution Case --- p.40 / Chapter 3.4 --- Numerical Examples --- p.51 / Bibliography --- p.55

by Kit-ching To. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 64-67). / Abstract also in Chinese. / Chapter Chapter 1 --- Overview --- p.1 / Chapter Chapter 2 --- Geometric Process Model --- p.6 / Chapter 2.1 --- Introduction --- p.6 / Chapter 2.2 --- Some Properties of Geometric Process --- p.7 / Chapter 2.3 --- Geometric Process Model for the Exponential Distribution --- p.13 / Chapter Chapter 3 --- Analysis of Warranty Policy by a Geometric Process Model --- p.16 / Chapter 3.1 --- Introduction --- p.16 / Chapter 3.2 --- Consumer's Policy --- p.17 / Chapter 3.2.1 --- N-Repair Warranty Policy --- p.19 / Chapter 3.2.2 --- n-Renewal Warranty Policy --- p.23 / Chapter 3.2.2.1 --- Modified n-Renewal Warranty Policy --- p.25 / Chapter 3.2.3 --- Optimal Policy to Consumer --- p.29 / Chapter 3.3 --- Manufacturer's Policy --- p.33 / Chapter 3.3.1 --- Optimal Policy to Manufacturer --- p.36 / Chapter 3.4 --- Numerical Examples --- p.38 / Chapter Chapter 4 --- Analysis of a Repairable M/M/l Queueing System by a Geometric Process Model --- p.45 / Chapter 4.1 --- Introduction --- p.45 / Chapter 4.2 --- Model --- p.46 / Chapter 4.2.1 --- Some Reliability Indices --- p.53 / Chapter 4.2.1.1 --- Availability --- p.53 / Chapter 4.2.1.2 --- Rate of Occurrence of Failures (ROCOF) --- p.54 / Chapter 4.3 --- Numerical Method --- p.56 / Chapter 4.3.1 --- Results --- p.58 / Bibliography --- p.64