Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, February 2004. / Includes bibliographical references (leaves 41-42). / With rapid economic growth, China attracts many multinational corporations (MNCs) as a manufacturing center with both its cheap labor cost and a huge consumer market. While doing business in China, most MNCs have faced logistical problems in connection with the transportation of their materials and the flow of information. The research objective of this paper is to describe the current state of Chinese logistics service and identify the logistics barriers that foreign firms have encountered in China. Dell and Wal-Mart are selected as case studies. The thesis analyzes their operating strategies and solutions to various problems they encountered in China and makes some recommendations. / by Manqin Luo. / M.Eng.in Logistics

Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, 2011. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 608-630). / This research is motivated by the National Academy of Engineering and the Institute of Medicine's joint call for research in healthcare, promoting the application of principles, tools, and research from engineering disciplines, and complex systems in particular. In 2005, the US healthcare expenditure represented 16% of its GDP, with hospitals representing the largest source of expenditure, as is the case in the United Kingdom. Consequently, the strategies and operations developed and implemented by hospitals have a significant impact on healthcare. Today, it would be hard to find a hospital that is not implementing a Lean initiative or who isn't familiar with its concepts. However, more often than not, their approach has narrowly focused at a process level and inside individual service units like an emergency department. This research seeks to elevate traditionally narrow hospital definitions of lean and explore the broader concepts of lean enterprise principles and Enterprise Architecture (EA) while enhancing our knowledge of hospitals' socio-technical complexity and enriching an emerging EA Framework (EAF) developed at the Massachusetts Institute of Technology (MIT). Following an extensive longitudinal multidisciplinary literature review, a number of expert interviews, and preliminary empirical findings, an exploratory inductive and deductive hybrid study was designed to collect and concurrently analyze both qualitative and quantitative empirical data from multiple hospital settings over two main phases: * The first phase consisted of recorded interviews with the Chief Executive Officers of seven leading Massachusetts hospitals, who also provided sensitive internal strategy and operations documents. We explored how hospitals currently measure their hospital performance and how their explicit and implicit practices may be improved using lean enterprise principles. e The second phase comprised two in-depth case studies of large leading multidisciplinary hospitals, one located in the US and other in the United Kingdom, and included a total of 13 embedded units of analysis. Multiple sources of evidence were collected including electronic medical records, 54 interviews, observation, and internal documents. Findings were categorized and sorted, as phenomena of interest consistently emerged from the data, and enriched both the EAF, and our understanding of hospitals' EA in particular. In both in-depth hospital cases we found that their EA consisted of multiple internal architectural configurations, and in particular, those with an enriched understanding of EA had made decisions which had improved not only their local performance, but also enhanced their interactions with other service units upstream and downstream. Conversely, worse performing configurations demonstrated a limited understanding of their hospital's EA. We conclude that hospital performance can be improved through an enriched understanding of hospital EA. Furthermore, whilst considering all hospitals included in this study, we propose general and specific recommendations, as well as diagnostic questions, performance dimensions, and metrics, to assist senior hospital leaders in architecting and managing their enterprise. / by Jorge Miguel dos Santos Fradinho. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Biological Engineering Division, 2006. / Includes bibliographical references (leaves 108-122). / Many liver physiological and pathophysiological behaviors are not adequately captured by current in vitro hepatocyte culture methods. A 3D perfused microreactor previously demonstrated superior hepatic functional maintenance than conventional 2D cultures, and was hypothesized to provide an environment favorable to endothelial cell maintenance and morphogenesis. This dissertation focuses on characterizing the 3D perfused co-culture of primary hepatocyte fraction with primary rat liver endothelial isolate. Scanning electron microscopy revealed significantly higher numbers of pore-like structures on the co-culture tissue surface resembling liver sinusoids compared to cultures containing only the hepatocytes fraction (mono-culture). EGFP-labeled endothelial cells proliferated moderately and organized into microvessel-like structures as observed by in situ multi-photon microscopy. By mixing female endothelial cells with male hepatocytes, the female cell population increased from initially -7% on day 1 to -12% on day 13, as determined by quantitative PCR on genomic DNA. The maintenance and morphogenesis of endothelial cells were not observed in parallel 2D collagen gel sandwich cultures. Immunohistochemistry further confirmed the presence of sinusoidal endothelia within the 3D co-culture tissue, as well as other non-parenchymal cells in both 3D mono-culture and co-culture. / (cont.) Global transcriptional profiling confirmed the loss of endothelia in 2D culture as the comparison between mono-culture and co-culture showed substantial differential expression levels only in the 3D format. The majority of the genes expressed substantially higher in 3D co-culture than mono-culture was found to be endothelia-specific. A group of key liver metabolism genes, however, do not show significant expression differences between the 3D cultures. This study concludes that the 3D perfused microreactor maintains non-parenchymal cells better than the 2D format, and the retention of non-parenchymal cells in the primary hepatocyte fraction likely contributes to the maintenance of key hepatic function gene expression. Additional endothelial cells organize into microvessel-like structures in this environment, but exert little influence on the gene expression of most key liver transcription factors and metabolism enzymes. Therefore 3D cultures may eliminate the need of co-cultures for applications focusing on metabolic behaviors of hepatocytes, and 3D endothelial-hepatocyte co-cultures may prove useful in studies where proper endothelium structure is required, such as cancer metastasis. / by Albert J. Hwa. / Ph.D.

Thesis (S.M.)--Massachusetts Institute of Technology, Engineering Systems Division, 2012. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 78-80). / The chemical processing industry has faced challenges with achieving improvements in safety performance, and accidents continue to occur. When accidents occur, they usually have a confluence of multiple factors, suggesting that there are underlying complex systemic problems. Moreover, accident investigations often reveal that accidents were preventable and that many of the problems were known prior to those accidents, suggesting that there may have been early warning signs. System-based analysis addresses systemic aspects and leading indicators enable the detection of ineffective controls and degradation of the system. Together, they could enable taking needed actions before an incident or a loss event. To develop process safety indicators, the chemical processing industry currently uses guidelines that are mainly based on the concepts of the "Swiss Cheese Model" and the "Accident Pyramid." The current guidelines lack a systemic approach for developing process safety indicators; the guidelines view indicators as independent measures of the safety of a system (e.g. a failure of a barrier), which can be misleading because it would not identify ineffective controls, such as those associated with the migration of the system towards an unsafe state, or associated with interdependencies between barriers. Moreover, process safety indicators that are currently used in the chemical industry are more focused on lagging as opposed to leading indicators. This main objective of this thesis is to develop a structured system-based method that can assist a hydrocarbon/chemical processing organization in developing system-based process safety leading indicators. Building on developed safety control structures and the associated safety constraints, the proposed method can be used to develop both technical and organizational leading indicators based on the controls, feedbacks, and process models, which, ultimately, can ensure that there is an effective control structure. / by Ibrahim A. Khawaji. / S.M.

Thesis (Ph. D. in Genetic Toxicology)--Massachusetts Institute of Technology, Biological Engineering Division, 2003. / Includes bibliographical references. / Although homologous recombination provides an efficient means for repairing and tolerating DNA damage, mitotic recombination between misaligned sequences can lead to loss of genetic information (e.g. deletions, translocations and loss of heterozygosity). Given that such genetic changes may promote tumorigenesis, it is critical to identify those genetic and environmental factors that render cells susceptible to homologous recombination. Our goal is to elucidate the mechanisms of DNA damage-induced recombination and to determine the role of DNA repair enzymes in modulating homologous recombination in eukaryotic cells. Alkylating agents are abundant in our environment and are generated endogenously as normal metabolites. In addition to their mutagenic and cytotoxic effects, alkylating agents stimulate homologous recombination in eukaryotic cells. Removal of alkylated bases by DNA glycosylases, such as the Magl 3-methyladenine (3MeA) DNA glycosylase, initiates the base excision repair (BER) pathway. To investigate the molecular basis for methylation-induced homologous recombination in S. cerevisiae, intrachromosomal recombination was measured under conditions where MAGI expression levels were varied. Cells lacking Magl show increased susceptibility to methylation-induced recombination, suggesting that unrepaired 3MeA lesions induce recombination. Overexpression of M4GI also elevates recombination levels, presumably due to the accumulation of recombinogenic BER intermediates. / (cont.) To study the relative importance of specific DNA repair enzymes in modulating recombination in mammals, we have engineered transgenic mice that make it possible to quantify homologous recombination events in primary somatic cells, both in vitro and in vivo. The FYDR (fluorescent yellow direct repeat) mice carry two different mutant copies of an expression cassette for enhanced yellow fluorescent protein (EYFP) arranged in a direct repeat. Homologous recombination between these truncated sequences restores expression of EYFP. Using flow cytometry, spontaneous and DNA damage-induced recombination events were quantified in primary fibroblasts cultured from embryonic and adult tissues. In addition, recombination events that occurred in vivo were detected directly in disaggregated skin cells. Currently, FYDR mice are being crossed with mice carrying engineered defects to determine how specific gene traits modulate susceptibility to mitotic recombination. Ultimately, this tool will help us better understand how environmental agents and specific genes influence cellular susceptibility to cancer-promoting recombination events in mammals. / by Carrie A. Hendricks. / Ph.D.in Genetic Toxicology

Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2003. / Includes bibliographical references (leaf 37). / by Daguang Zhang. / M.Eng.in Logistics

Thesis (M.Eng.)--Massachusetts Institute of Technology, Engineering Systems Division, 2000. / Includes bibliographical references (leaves 75-77). / Market leadership requires effective management of product life cycle, starting from the launch of a new product until its retirement. In this particular project, an exploratory study of business practices in the management of products in the decline phase and the eventual decision of product abandonment is conducted through surveys and interviews of senior executives from Fortune 500 companies, focusing mainly on food, networking equipment, medical devices, consumer electronics and retail industries. Actual names of the companies are not revealed for confidentiality reasons. Also, the implementations, assumptions and level of acceptance of decision support system (DSS) modules on product lifecycle management are analyzed. Finally, companies' business processes are compared and enhancements to current DSS systems are proposed. / by Gokhan Usanmaz. / M.Eng.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, 2006. / Includes bibliographical references (p. 131-140). / How do enterprises successfully conceive, design, deliver, and operate large-scale, engineered systems? These large-scale projects often involve high complexity, significant technical challenges, a large number of diverse stakeholders, distributed execution, and aggressive goals. In this context, simultaneously meeting technical performance, cost, and schedule goals effectively and efficiently is a serious challenge. In fact, it is rarely accomplished. The nature of an enterprise contributes to this challenge. Enterprises are interorganizational networks with distributed leadership and stakeholders with both common and diverse interests. They are unique from traditional levels of analysis in organizational studies, and in general their behavior is not well understood. They are a prevalent form of organizing work in these large engineering projects, where one organization simply does not have the capability or willingness to take on the entire project by themselves. This work explores the factors that distinguish high performance enterprises from those that are less successful in these large-scale projects. The setting for this research is programs in the aerospace industry. / (cont.) A comparative case study method was used to study nineteen programs spanning the U.S. (mainly defense) aerospace industry in order to develop grounded theory regarding contemporary program execution strategies and distinguishing attributes. Drawing on prior research with high performance teams, several characteristics were explored and refined, eventually resulting in identification of ten best practices. The contribution of this work is codification of these best practices into a coherent framework of complementary elements relating to particular outcomes. The framework articulates three drivers of individual and systemic behaviors: a system of distributed leadership, informal and formal structures. The framework addresses the role each of these plays in enterprise performance. The synergistic combination of the elements enables enterprises to execute planned activities, leverage emergent opportunities, and deal with unforeseen circumstances. For enterprises involved in large-scale engineering projects, these capabilities are a necessity for success. In addition to an academic theory, this framework can be considered an architectural design for high performance enterprises. Putting this enterprise architecture into practice has important implications for both corporate and program management. / by Alexis Kristen Stanke. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, 2013. / Page 163 blank. Cataloged from PDF version of thesis. / Includes bibliographical references (p. 129-137). / This research develops a novel approach to long-term power system capacity expansion planning for developing countries by incorporating endogenous demand dynamics resulting from social processes of technology adoption. Conventional capacity expansion models assume exogenous demand growth; however, literature suggests that this assumption is not appropriate for developing countries. The planning approach presented in this research explicitly represents the links between the social and technical components of the power system. As potential customers without electricity select between various supply options to meet their power needs and as existing customers alter their consumption in reaction to the price of electricity and the perceived performance of the grid, the demand for grid power is directly impacted. This thesis demonstrates that neglecting these feedbacks and resorting to simplified assumptions can result in suboptimal investment strategies. By comparing the investment strategies identified using this novel approach to that of more conventional approaches, this research highlights cases in which the incorporation of endogenous demand impacts capacity expansion planning. More specifically, this work proves that incorporating endogenous electricity demand is important when there is a large fraction of the population without access to power or when the improvement in reliability afforded by capacity expansion is large. Employing traditional capacity expansion methods in such cases may lead to the selection of inferior expansion strategies. This research has both academic and applied contributions. Methodologically, this research extends state-of-the-art power system models by combining two generally separate modeling approaches, system dynamics and optimization. These methods are integrated to capture both the technical details of power grid operation and endogenous electricity demand dynamics in order to simulate the performance and evolution of the electric power grid. This research also demonstrates a holistic approach to centralized power planning that enables a more realistic representation of grid demand in developing countries and the identification of strategies that, in some cases, perform better than the strategies identified using traditional approaches. Finally, while this research was inspired by the case of Tanzania, the approach was developed with the flexibility to be applied to other countries with similar power system structure and contextual features. / by Rhonda LeNai Jordan. / Ph.D.

Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2009. / Includes bibliographical references (leaves 91-95). / Perishability and stock-outs are two sources of inventory inefficiency in the Washington State tree fruit industry. This thesis measures the size of these inefficiencies in terms of dollars per box, and describes five solutions, four qualitative and one quantitative, that seek to address them. To establish the magnitude of the inefficiencies, I regress various fruit characteristics on a set of sales data, thereby ascertaining the relationship between a fruit's price and its age. I find that the industry loses 5% to 12% of potential revenue due to perishability and propose four qualitative policies designed to reduce these losses. Next, I develop an operational management tool in the form of a mixed-integer optimization model which can be used to make optimal sourcing decisions during stock-out events. I find that the potential savings from improved sourcing decisions are between $0.01 and 0.02 per box. These results confirm that the costs and foregone revenue associated with inventory management are significant and merit the tree fruit industry's attention. / by Jame Sterling Foreman. / M.Eng.in Logistics