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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.

Multidisciplinary design problem solving on product development teams

Bernstein, Joshua I. (Joshua Ian), 1974- January 2001 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Sloan School of Management, Technology, Management, and Policy Program, February 2001. / Includes bibliographical references (p. 197-216). / This investigation, conducted under the auspices of the Lean Aerospace Initiative (LAI), studied how engineers from different specialties interpret and communicate about technical design problems while working on product development teams. Data was collected on 98 cases via interviews with engineers at LAI member companies. For approximately one-third of the cases, two engineers with different backgrounds were interviewed, allowing comparisons to be made between their descriptions of the problems under study. For the remaining cases, one interview was conducted per case. The most important finding of this study was that engineers from different specialties do interpret the same problem differently. Specifically, two engineers were likely to evaluate the benefits or drawbacks of a potential solution using different sets of criteria. Thus, some design disputes were the result not of mutually exclusive needs but of a failure to recognize the different ways in which engineers were evaluating solutions to the problem. Furthermore, data collected during this study illustrated that in some cases these differences were the result of engineers addressing related, but unique problems. Therefore, a solution to one engineer's problem often created a new problem for another engineer on the team. / (cont.) A second conclusion of this study was that how design tools were used had a greater impact on a team's problem solving abilities than what tool was used. In this context, design tools included objects such as real or "virtual" prototypes as well as processes like simulations and tests. The results of this investigation suggested that such tools offered their greatest benefits when they were used in a participatory fashion in which a large fraction of a team shared in their use. Additionally, the more elements of a problem's context that were captured in a design tool, the greater its utility. Under such conditions, team members were able to create a shared evaluation system to judge potential solutions to the problem they were confronting, thereby facilitating problem resolution. Based on these results, the traditional model of engineering communication derived from the information processing framework requires modification. The information processing model assumes that individuals have a shared understanding of meaning when they communicate. This study, however, suggests that such shared understandings do not exist in advance, but are instead ... / by Joshua I. Bernstein. / Ph.D.

Modeling and analyzing cost, schedule, and performance in complex system product development

Browning, Tyson R January 1999 (has links)
Thesis (Ph.D.)--Massachusetts Institute of Technology, Sloan School of Management, Technology, Management, and Policy Program, February 1999. / Includes bibliographical references. / In the future, it is unlikely that complex system products will compete solely on the basis of technical performance. What will differentiate such systems and their developers is the ability to balance all the dimensions of product performance, including product pricing and timing (which are functions inclusive of development cost and cycle time). Furthermore, this balance must be congruent with customers' perceptions of value. Once this value is ascertained or approximated, complex system developers will require the capability to adjust the design process to meet these expectations. The required amount and sophistication of project planning, control, information, and flexibility is unprecedented. The primary goal of this work is a method to help managers integrate process and design information in a way that supports making decisions that yield products congruent with customer desires and strategic business goals. This work consists of three parts. Part one contains two exploratory studies that further understanding of complex system product development processes. One study explores process iteration and seeks to explain why some aircraft development programs do not address iteration with existing project planning and control methods. The other study examines sources of risk, classifying these into six categories (cost, schedule, performance, technology, business, and market risks) and building causal frameworks to represent their relationships. Both studies point to avenues for improving existing process '·models and in some cases reveal process characteristics requiring new methods. These results, while derived from projects in the aerospace industry, are highly applicable across a variety of complex system development projects. Part two entails an effort to model some of the characteristics observed in part one. After a review of four types of dependency structure matrices (DSMs), notably the activity-based or schedule DSM, extensive data are collected from an uninhabited aerial vehicle (UAV) design process. Part two thus describes how to build a DSM model and provides data for example applications of the detailed models developed in part three. Based on the foundational work of parts one and two, part three develops a new methodology and models for understanding product development process cost, schedule, and performance. The methodology complements activity-centric schedule models such as DSM in that activities provide direct contributions to process cost and schedule and design performance. This approach sets the stage for integrated cost, schedule, and performance analyses. A cost and schedule model is presented first, and it is extended to account for the effects of activities on product performance. The stochastic, simulation model generates distributions of possible cost, schedule, and performance outcomes. These distributions represent uncertainty and are analyzed in relation to impact functions and targets to determine levels of risk. The model outputs enable the exploration of the costs and benefits of several management options and yield interesting insights. The goal is to improve product development planning and control though the capability to balance cost, schedule, and performance appropriately. / by Tyson Rodgers Browning. / Ph.D.

Networking technology adoption : system dynamics modeling of fiber-to-the-home

Kelic, Andjelka, 1972- January 2005 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, Technology, Management, and Policy Program, 2005. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Page 244 blank. / Includes bibliographical references (p. 241-243). / A system dynamics model is developed and run to study the adoption of fiber-to-the-home as a residential broadband technology. Communities that currently do not have broadband in the United States are modeled. This case is of particular interest to U.S. policymakers, but also relevant to other regions concerned with economic development in rural areas. The model is used to explore the effects of government policy on fiber-to-the-home deployment and on the telecommunications supply chain. The research finds that government policy relating to broadband deployment has been based on a weak understanding of the dynamics involved, resulting in trial and error policy making that has unintended consequences. The thesis shows that the current monitoring of broadband deployment by the Federal Communications Commission is inadequate to contribute to the formation of reasoned policy decisions. The model is used to explore the consequences that different regulatory scenarios have on fiber-to-the-home deployment. Among the policy choices considered are: resale of fiber-to-the-home lines to competitive providers; low cost government loans for commercial deployments; rapid deployment to all communities currently without service; and a ban on municipal deployments. The current Rural Utilities Service loan program is also included in the model and its effects are analyzed. The model is used to examine the consequences for the optoelectronics industry of different deployment scenarios. It shows that the interests of consumers, regulators, and even service providers are in conflict with the interests of the optoelectronics industry which provides a critical component necessary for the service. / (cont.) Strategies to help mitigate that conflict and to promote the health of the components industry are explored. Deployment of fiber-to-the-home is costly, and cost recovery is difficult for both incumbent and competitive service providers, especially in rural and suburban regions that do not currently have service. The interests of policy makers, service providers, and component suppliers need to be aligned to implement effective policy that encourages the deployment of broadband to unserved regions. The Federal Communications Commission needs to rearchitect its monitoring of service providers and their activities to better understand the status of deployment and how its policies can help or hinder. / by Andjelka Kelic. / Ph.D.

Approximate life-cycle assessment of product concepts using learning systems

Sousa, Inês (Maria Inês Silva Sousa), 1972- January 2002 (has links)
Thesis (Ph. D. in Environmental Systems Design)--Massachusetts Institute of Technology, Engineering Systems Division, Technology, Management, and Policy Program, 2002. / Includes bibliographical references (p. 143-150). / This thesis develops an approximate, analytically based environmental assessment method that provides fast evaluations of product concepts. Traditional life-cycle assessment (LCA) studies and their streamlined analytical versions are costly, time-consuming, and data intensive. Thus, they are not practical to apply during early concept design phases where little information is available and ideas change quickly. Alternatives currently used are mostly qualitative, ad-hoc approaches that often provide overly simplistic assessments difficult to trade-off with other design objectives. The Learning Surrogate LCA method is an alternative approach that uses simple, high-level, and accessible descriptive information about a product to provide approximate, yet useful, analytical LCA results during early concept design stages. The method relies on a general artificial neural network (ANN) trained on high-level product descriptors and environmental performance data from pre-existing detailed life-cycle assessment studies or related data. To quickly obtain an approximate environmental impact assessment for a product concept, the design team queries the trained artificial model with new set of descriptors, without requiring the development of a new model. The predicted environmental performance, along with other key performance measures, can be used in tradeoff analysis and concept selection. Foundations for the approach were established by investigating: (1) model inputs in the form of a compact, and meaningful set of product concept descriptors; (2) ability to gather data and appropriately train an ANN-based surrogate LCA model. / (cont.) Proof-of-concept tests on life-cycle energy consumption showed that ANN-based surrogate models were able to: (a) match detailed LCA results within the accuracy of typical LCA studies; (b) predict relative differences of distinct product concepts; (c) correctly predict and generalize trends associated with changes for a given product concept. A product classification system based upon concept descriptors was developed to improve performance. The method was then applied to a case study with a heavy truck manufacturing company. A demonstration example was used to illustrate application scenarios for tradeoff analysis within DOME (Distributed Object-based Modeling Environment). The study suggested that high-level, customizable simulation interfaces of learning surrogate LCA models are likely to have a significant practical impact in the early decision making process. / by Inês Sousa. / Ph.D.in Environmental Systems Design

Guardians at the Gates of Hell : estimating the risk of nuclear theft and terrorism -- and identifying the highest-priority risks of nuclear theft

Bunn, Matthew January 2007 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, Technology, Management, and Policy Program, 2007. / Includes bibliographical references (p. 419-466). / Methods are presented to assess the global risk of nuclear theft and nuclear terrorism, to identify the nuclear facilities and transport legs that pose the highest-priority risks of nuclear theft, and to evaluate policy approaches to strengthening security and accounting for nuclear stockpiles worldwide. First, a qualitative assessment outlines the demand for black-market nuclear weapons and materials; the plausibility of terrorist construction of an improvised nuclear device; the global stocks and flows of nuclear weapons, plutonium, and highly enriched uranium (HEU), with the global distribution of facilities where they exist; and the widely varying standards of physical protection, control, and accounting in place to prevent theft. Particular dangers of nuclear theft in Russia, Pakistan, and from HEU-fueled research reactors are highlighted. Second, a mathematical model of the global risk of nuclear terrorism is presented, with detailed assessments of what is known about the values of each of the parameters, and of policies that could change each of the parameters to reduce risk. / (cont.) Third, a methodology for identifying the nuclear facilities and transport legs posing the highest risks of nuclear terrorism is presented, combining the security levels for each facility or transport leg, the levels of threat they face, and the quantity and quality of nuclear weapons or weapons-usable material they contain. Fourth, the global nuclear security system is described and assessed as a complex, large-scale, integrated, open system (CLIOS). Based on past experiences with different policy tools from negotiated international standards to on-the-ground technical cooperation to install improved security equipment, options to improve system performance in reducing the risk of nuclear terrorism are assessed. A final chapter offers conclusions and recommendations. / by Matthew Bunn. / Ph.D.

Technological change for environmental improvement : the case of the Mexican automobile sector

Aoki, Chizuru, 1968- January 2002 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Sloan School of Management, Technology, Management, and Policy Program, 2002. / Includes bibliographical references (p. 224-235). / The main objective of this research was to articulate the processes and factors of technological change that promote environmental improvement while contributing to development goals in the Mexican automobile sector. The motivation stemmed from the need for air pollution mitigation in the Mexico City Metropolitan Area (MCMA). The research analyzed three cases of environmental technology introduction in passenger vehicles, and synthesized the case findings into a conceptual model. The case studies were complemented with quantitative analyses of parameters of national technological capability acquisition, and scenario analysis of emission mitigation potential. The research showed that environmental technological change in the Mexican auto sector is increasingly influenced by external factors, specifically global sector development and conditions in countries with major auto producers and export markets. Environmental technological change could be articulated within the framework of conventional technological change, with some differences, such as: the need to account for environmental policy as a distinct factor, different motivations of private sector actors in acquiring technological capabilities and deploying technology, and interactions and conflicts between environmental policy and other factors, which can create barriers. The research found that environmental policy is a necessary but not sufficient factor to induce environmental technological change in Mexico. Environmental policy did and does influence environmental technological change by specifying the time and pacing of technology introduction. The scenario analysis showed the projected effectiveness of technology options. / (cont.) Recommendations for the Mexican policymakers include: (1) the role and limitations of environmental policy in the process of environmental technological change should be recognized; (2) policymakers should strive to minimize institutional fragmentation, which undermines policy implementation; (3) vehicle technology options should be considered further, due to their effectiveness, and political and institutional feasibility; (4) the environmental authorities are likely to encounter opposition to Mexico-specific technology requirements, particularly if they are more stringent than in the US or Europe; and (5) the authorities' ability to benefit from the export platform to introduce advanced technologies in Mexico will be diminished if export markets shift towards markets with less stringent emission standards than the US and Europe. / by Chizuru Aoki. / Ph.D.

Linking modularity and cost : a methodology to assess cost implications of product architecture differences to support product design

Fixson, Sebastian K. (Sebastian Klaus), 1967- January 2002 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, Technology, Management, and Policy Program, 2002. / Includes bibliographical references (p. 239-255). / Reaching saturation levels, many markets in modem industrial societies tend to fracture into smaller 'niche' markets, and create a need for greater variety. At the same time, increasing product variety in non-growing markets results in decreasing production volumes per model, which tends to increase costs. Modularity as a design concept has been suggested to be able reconciling these opposing effects. Most descriptions of modularity characterize products through idealized extremes, such as 'modular' versus 'integral.' While conceptually powerful, this notion is very difficult to operationalize. Consequently, it has been very problematic to determine the economic consequences of modularity. This thesis presents a methodology to overcome this problem. The development of the methodology is split into three parts: what is modularity, what costs are considered, and how can the link between the two be established? First, to operationalize modularity, an in-depth analysis of the phenomenon was conducted and an alternative framework developed. The multi-disciplinary analysis revealed that modularity is a bundle of product characteristics rather than an individual feature, and that different disciplines and viewpoints emphasize different elements of this bundle. Consequently, the descriptive product architecture framework developed in this thesis encompasses all dimensions identified in the analysis, but simultaneously enables one to comparatively measure those characteristics along individual dimensions. / (cont.) Second, to improve the understanding of the multitude of costs that occur over a product's life, a product life-cycle view has been used to investigate the cost effects of early design decisions with respect to product architecture. In addition, a review of the cost modeling literature identified the gap that exists between some empirical work identifying particular product features' effects on particular costs, and the more general design guidelines such as design-for-manufacturing (DFM) or design-for-assembly (DFA). Finally, the thesis constructed a link between modularity and cost by applying the product architecture framework and technical cost modeling to experimental case studies. Case study subjects were four different car door structures. The case studies demonstrate the cost consequences of individual product architecture dimensions by isolating their effects from competing explanations. Enabling the translation of business goals into focused design advice, the proposed methodology represents a tool to reconnect management and engineering worlds. / by Sebastian K. Fixson. / Ph.D.

Beating the system : accelerating commercialization of new materials

Musso, Christopher Scott, 1974- January 2005 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, Technology, Management, and Policy Program, February 2005. / Includes bibliographical references (p. 233-249). / Over the past century, materials have faced notoriously long delays between invention and commercialization. These delays make private investment very difficult, and can prevent good materials from reaching markets. A systematic exploration of the commercial histories of major commodity thermoplastics was performed, which showed that these delays were attributable to technical deficiencies in materials and obstacles in the application value chains. Contrary to popular wisdom, material costs, competitive materials, and serendipity were much smaller factors in commercialization delay. The factors that led to insertion of plastics into applications were different from the factors that led to post-insertion growth. The major plastics showed a characteristic pattern of commercialization. First, they entered simple, small applications in which they solved new problems. They then progressed to achieve insertion in a single major application, which they continue to dominate today. Having established themselves with this application, they found insertion in a wide range of large applications. The commercialization pattern can be explained in large part by the concept of switching costs. As knowledge of a material increases, switching costs are reduced; as value chain complexity increases, switching costs increase. The earliest applications required little understanding of plastics and had simple value chains, so switching costs were low, corresponding to fast commercialization. Later applications had more complex value chains and required much more detailed understanding of the failure modes and processing parameters of the material, corresponding to high switching costs and slow commercialization. Materials can be deployed into / (cont.) many markets. By strategically selecting application markets, materials producers can significantly improve the probability that new materials will be adopted and can shorten the period of commercialization. Early markets should be selected based on the ability of the material to solve unique problems and the simplicity of the application value chain. When market selection is not an option, materials producers can integrate forward in the value chain to shorten commercialization times, but capital requirements are very high. Once integrated into an application, the safest competitive position for materials is to be the lowest cost option that meets the exact needs of the application. / by Christopher Scott Musso. / Ph.D.

Liberalizing development : effects of telecommunication liberalization in Thailand and the Philippines / Effects of telecommunication liberalization in Thailand and the Philippines

Krairit, Donyaprueth January 2001 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Sloan School of Management, Technology, Management, and Policy Program, 2001. / Includes bibliographical references (leaves [149]-158). / This thesis hypothesized that extensive telecommunications liberalization would not increase the penetration rate of the fixed telephone service better than other, less competition-oriented, policy alternatives. The hypothesis was validated in the case of Thailand and the Philippines. However, for the cellular mobile telephone and Internet services, extensive telecommunications liberalization could increase the penetration rates better than other, less competition-oriented, policy alternatives. Thus, the thesis demonstrates that past research has not paid sufficient attention to this issue and has assumed that the more extensive reform could lead to the faster and the better telecommunications development of all telecommunication services. The thesis suggested that less-developed countries (LDCs) should realize that they do not have to fully implement liberalization reforms, but should instead specifically tailor their telecommunications reform policies to their own pace and needs. This study found that extensive liberalization reforms or extensive opening of the market does not necessarily increase penetration rates of services better than other less competition-oriented policy alternatives under the following conditions: Assuming that the services have not yet reached their saturation levels based on the S-curve, / (cont.) 1. Users perceive the service as a necessity; and 2. the government perceives the service as a basic necessity; and 3. the government strictly commits and implements purposeful policies with the intention of increasing penetration rates of the services through the distribution of service provision authority. Or, 4. If the liberalization is implemented after the saturation level of the service is reached. The thesis results have the policy implication that liberalization can be a useful and effective alternative to lead to higher penetration rates, when and only if, the country and its people understand its goals, effects and implications and, more importantly, when the government provides the policy framework for universal service for the benefits of its people so that the liberalization can lead to self-sustainable development. / by Donyaprueth Krairit. / Ph.D.

Induced technical change in computable general equilibrium models for climate-change policy analysis

Sue Wing, Ian, 1970- January 2001 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Sloan School of Management, Technology, Management, and Policy Program, 2001. / Includes bibliographical references (p. 329-352). / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Policies to avert the threat of dangerous climate change focus on stabilizing atmospheric carbon dioxide concentrations by drastically reducing anthropogenic emissions of carbon. Such reductions require limiting the use of fossil fuels-which supply the bulk of energy to economic activity, and for which substitutes are lacking-which is feared will cause large energy price increases and reductions in economic welfare. However, a key determinant of the cost of emissions limits is technological change-especially innovation induced by the price changes that stem from carbon abatement itself, about which little is understood.This thesis investigates the inducement of technological change by limits on carbon emissions, and the effects of such change on the macroeconomic cost of undertaking further reductions. The analysis is conducted using a computable general equilibrium (CGE) model of the US economy-a numerical simulation that determines aggregate welfare based on the interaction of prices with the demands for and supplies of commodities and factors across different markets. Within the model induced technical change (ITC) is represented by the effect of emissions limits on the accumulation of the economy's stock of knowledge, and by the reallocation of the intangible services generated by the stock, which are a priced input to sectoral production functions. / (cont.) The results elucidate four key features of ITC: (1) the inducement process, i.e., the mechanism by which relative prices determine the level and the composition of aggregate R&D; (2) the effects of changes in R&D on knowledge accumulation in the long-run, and of contemporaneous substitution of knowledge services within and among industries; (3) the loci of sectoral changes in intangible investment and knowledge inputs induced by emissions limits; and (4) the ultimate impact of the accumulation and substitution of knowledge on economic welfare. / by Ian Sue Wing. / Ph.D.

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