Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2008. / Includes bibliographical references (leaves 61-63). / A case study is presented of a successful quick serve fast food restaurant chain that uses inventory throughout the supply chain as a buffer against uncertainty in supply and demand. This is a common operational strategy in many industries, but it limits options for the supply chain to become more agile, adaptable, and aligned to the dynamic needs of the enterprise. Trade-offs between transportation and holding costs are illustrated. The drawbacks of assuring supply by maintaining inventory at the distribution center level are discussed. Supply chain alternatives are presented including lateral transfers, forward warehouses, alternative modes of transportation, and multiple suppliers. An analytical approach is presented which provides a total relevant supply chain cost at the distribution center level. The approach is illustrated in the decision between two alternative transportation modes with different average lead times, lead time variabilities, and transportation costs. / by Daniel Jonathon Stanton. / M.Eng.in Logistics

Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, 2006. / Includes bibliographical references (p. 141-151). / This thesis introduces a framework and two methodologies that enable engineering management teams to assess the value of real options in programs of large-scale, partially standardized systems implemented a few times over the medium term. This enables value creation through the balanced and complementary use of two seemingly competing design paradigms, i.e., standardization and design for flexibility. The flexibility of a platform program is modeled as the developer's ability to choose the optimal extent of standardization between multiple projects at the time later projects are designed, depending on how uncertainty unfolds. Along the lines of previous work, this thesis uses a two-step methodology for valuing this flexibility: screening of efficient standardization strategies for future developments in a program of projects; and valuing the flexibility to develop one of these alternatives. The criterion for screening alternative future standardization strategies is the maximization of measurable standardization effects that do not depend on future uncertainties. / (Cont.) A novel methodology and algorithm, called "Invariant Design Rules" (IDR), is developed for the exploration of alternative standardization opportunities, i.e., collections of components that can be standardized among systems with different functional requirements. A novel valuation process is introduced to value the developer's real options to choose among these strategies later. The methodology is designed to overcome some presumed contributors to the limited appeal of real options theory in engineering. Firstly, a graphical language is introduced to communicate and map engineering decisions to real option structures and equations. These equations are then solved using a generalized, simulation-based methodology that uses real-world probability dynamics and invokes equilibrium, rather than no-arbitrage arguments for options pricing. The intellectual and practical value of this thesis lies in operationalizing the identification and valuation of real options that can be created through standardization in programs of large-scale systems. This work extends the platform design literature with IDR, a semi-quantitative tool for identifying standardization opportunities and platforms among variants with different functional requirements. / (cont.) The real options literature is extended with a methodology for mapping design and development decisions to structures of real options, and a simulation-based valuation algorithm designed to be close to current engineering practice and correct from an economics perspective in certain cases. The application of these methodologies is illustrated in the preliminary design of a program of multi-billion dollar floating production, storage and offloading (FPSO) vessels. / by Konstantinos Kalligeros. / Ph.D.

Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2008. / Includes bibliographical references (leaves 64-65). / Managing a big supply chain for one of the largest quick service restaurant companies, especially when the company has a policy called "Never Run Out," is very challenging. A traditional way of managing inventory requires high level of safety stock if high level of uncertainty is involved. Sources of uncertainty include variability in demand from frequent promotions or seasonal effect, variability in order lead time from using low-cost mode of transportation, or lack of information sharing. This project developed an expediting policy with dual reorder points with demand threshold and tested the policy with a Monte Carlo simulation. Previous research on two reorder points provide great foundation for this study but they lack consideration on demand variability and approaches to set up reorder points. We propose an algorithm with a demand threshold to trigger an expedited order and heuristic approaches to develop reorder points where the total cost can be minimized while service requirements are met. / by Gil Su Lee. / M.Eng.in Logistics

Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2010. / Cataloged from PDF version of thesis. / Includes bibliographical references. / AAA, a large oil and gas field services company, is in the business of providing drilling services to companies that extract and market hydrocarbons. One of the key success factors in this industry is the ability to provide comprehensive drilling solutions on short notice and in demanding conditions; fast and reliable delivery of drilling equipment to well sites is critical to maintaining customer satisfaction and market share. The company is considering a reconfiguration of its tool distribution network in order to facilitate a more rapid and cost-effective delivery of drilling tools to drilling sites. Specifically, the company is considering using either a "pure" hub-and-spoke distribution setup, with one of its major facilities - OK - serving as a logistics hub, or a hub-and-spoke system with postponement capabilities, whereby the OK facility will also have certain assembly and configuration capabilities. This thesis develops a model of the AAA distribution network and creates a simulation of the flow of drilling tools through the two alternative network configurations. As customer service levels and logistics costs are evaluated under various levels of end-user demand, both network setups are shown to increase the effectiveness and cost-efficiency of tool deliveries. The key finding is that the hub-and-spoke with postponement design appears to be superior in terms of logistics costs and timely deliveries. / by Alexander Martchouk. / M.Eng.in Logistics

Thesis (S.M. in Technology and Policy)--Massachusetts Institute of Technology, Engineering Systems Division, 2013. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 60-62). / The Veterans Health Administration (VHA) provides care to over eight million Veterans and operates over 1,700 sites of care distributed across twenty-one regional networks in the United States. Health care providers within VHA report large seasonal variation in the demand for services, especially in healthcare systems located in the southern U.S. that experience a large influx of "snowbirds" during the winter. Since the majority of resource allocation activities are carried out through a single annual budgeting process at the start of the fiscal year, the seasonal load imposed by "traveling Veterans," defined as Veterans that seek care at VHA sites outside of their home network, make providing high quality services more difficult. This work constitutes the first major effort within VHA to understand the impact of traveling Veterans. We found a significant traveling Veteran population (6.6% of the total number of appointments), distributed disproportionately across the VHA networks. Strong seasonal fluctuations in demand were also discovered, particularly for the VA Bay Pines Healthcare System, in Bay Pines, Florida. Our analysis further indicated that traveling Veterans imposed a large seasonal load (up to 46%) on the Module A clinic at Bay Pines. We developed seasonal autoregressive integrated moving average (SARIMA) models to help the clinic better forecast demand for its services by traveling Veterans. Our models were able to project demand, in terms of encounters and unique patients, with significantly less error than the traditional historical average methods. The SARIMA model for uniques was then used in a Monte Carlo simulation to understand how clinic resources are utilized over time. The simulation revealed that physicians at Module A are over-utilized, ranging from a minimum of 92.6% (June 2013) to maximum 207.4% (January 2013). These results evince the need to reevaluate how the clinic is currently staffed. More broadly, this research presents an example of how simple operations management methods can be deployed to aid operational decision-making at other clinics, facilities, and medical centers both within and outside VHA. / by Shahed Al-Haque. / S.M.in Technology and Policy

Thesis (Sc. D.)--Massachusetts Institute of Technology, Biological Engineering Division, February 2007. / Includes bibliographical references (leaves 108-124). / Our understanding of why biological systems are designed in a particular way would benefit from biophysically-realistic models that can make accurate predictions on the time-evolution of molecular events given arbitrary arrangements of genetic components. This thesis is focused on constructing such models for gene expression during bacteriophage T7 infection. T7 gene expression is a particularly well suited model system because knowledge of how the phage functions is thought to be relatively complete. My work focuses on two questions in particular. First, can we address deficiencies in past simulations and measurements of bacteriophage T7 to improve models of gene expression? Second, can we design and build refactored surrogates of T7 that are easier to understand and model? To address deficiencies in past simulations and measurements, I developed a new single-molecule, base-pair-resolved gene expression simulator named Tabasco that can faithfully represent mechanisms thought to govern phage gene expression. I used Tabasco to construct a model of T7 gene expression that encodes our mechanistic understanding. The model displayed significant discrepancies from new system-wide measurements of absolute T7 mRNA levels during infection. / (cont.) I fit transcript-specific degradation rates to match the measured RNA levels and as a result corrected discrepancies in protein synthesis rates that confounded previous models. I also developed and used a fitting procedure to the data that let us evaluate assumptions related to promoter strengths, mRNA degradation, and polymerase interactions. To construct surrogates of T7 that are easier to understand and model, I began the process of refactoring the T7 genome to construct an organism that is a more direct representation of the models that we build. In other words, instead of making our models evermore detailed to explain wild-type T7, we started to construct new phage that are more direct representations of our models. The goal of our original design, T7. 1, was to physically define, separate, and enable unique manipulation of primary genetic elements. To test our initial design, we replaced the left 11,515 bp of the wild-type genome with 12,179 bp of engineered DNA. The resulting chimeric genome encodes a viable bacteriophage that appears to maintain key features of the original while being simpler to model and easier to manipulate. I also present a second generation design, T7.2, that extends the original goals of T7.1 by constructing a more direct physical representation of the T7 model. / by Sriram Kosuri. / Sc.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Biological Engineering Division, 2008. / Includes bibliographical references (leaves 66-75). / Eight distinct nuclear shapes, or morphologies, have been discovered in human proto-organs and tumors, including bell-shaped nuclei with stem-like properties. These bell-shaped, or "metakaryotic," nuclei are abundant in fetal tissues and neoplasias, but rare in normal adult somatic tissues. Metakaryotic nuclei employ an unusual process for division in which DNA synthesis, partial genomic condensation, and separation of the two nuclei in a cup-from-cup fashion occur concurrently, as shown by Feulgen densitometry and single-stranded DNA assays by Dr. Elena Gostjeva. This is clearly different from the sequential steps of S-phase DNA synthesis, chromatin condensation, chromosomal separation, and genomic segregation that occur in mitotic eukaryotic cells. In order to discover how a genome apparently devoid of chromosomes might be organized, this thesis focused on recognizable DNA sequences common to all chromosomes: centromeres and telomeres. Fluorescence In Situ Hybridization (FISH) with pan-centromeric and pan-telomeric probes was applied to samples of human tissue. (A collaborating lab used centromeric and telomeric antibodies to confirm results.) An optimized FISH protocol was developed specifically for metakaryotic nuclei and tested in both human cell lines and eukaryotic cells as experimental controls. Staining of metakaryotic nuclei resulted in approximately 23 centromeric regions in each, unlike the expected number of 46 regions seen in eukaryotic nuclei. Many of these staining regions contained paired centromere signals, or doublets. This suggested a genomic organization of homologous chromosomes paired at their centromere regions. If this were the case, one would expect 46 telomeric signals per nuclei, if telomeres were also homologously paired. / (cont.) Unexpectedly, an average of 23 telomeric regions were found in many, if not all, bell-shaped metakaryotic nuclei. This, along with the observation of a condensed double ring around the mouth of the bell-shaped nuclei, suggested the possibility of a genome organized as paired, continuous genomic circles. Studies of telomere joining in metakaryotic nuclei by Dr. Per Olaf Ekstrom have provided further evidence for the paired genomic circle model. The results in this thesis are an original contribution to the field of stem cell physiology, a starting point for further investigation of DNA organization, synthesis, and repair in these metakaryotic cells, and hopefully will lead to a greater understanding of human development, growth, and cancer. / by Amanda Natalie Gruhl. / Ph.D.

Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2010. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 62-63). / Global operation strategies have been widely used in the last several decades as many companies and industries have taken advantage of lower production costs. However, in choosing a location, companies often only consider labor cost and, as a result, overall costs may not be reduced. What other costs besides labor should be considered in locating a global facility? This research examines sourcing, manufacturing and distribution costs and develops a total landed cost model for global operations. We use this total landed cost model to estimate the total cost from raw material to the customer for one sample company operation, Tyco Electronics, across multiple manufacturing and customer countries. This total landed cost model was used to analyze the cost for each manufacturing location, customer, and mode of transportation as well as predict the effect from risks and uncertainties in global supply chain. / by Apichart Jearasatit. / M.Eng.in Logistics

Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2010. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 73). / There is no doubt that the 21st century is the century of globalization. The great majority of companies' supply chains span multiple countries, cultures, and industries. However people in different parts of the globe perceive supply chain risks differently. Is it possible to predict the way people manage their supply chain in terms of prevention versus response, based on demographics? Using a large-scale worldwide, online survey as a base, conducted by the MIT Global SCALE Initiative, this research project analyzes the relationship between a dependent variable (Prevention vs. Response) and independent variables (demographics). The analysis shows that there are indeed demographic factors that can help predict how people manage supply chain risk. The following demographic factors need to be known: country of origin, gender, primary field of study, and job function. / by Nuno Miguel Mendes Toste Dinis. / M.Eng.in Logistics

Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2003. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Includes bibliographical references (leaf 29). / Following the incidents of 9/11, the FAA imposed new restrictions on cargo to be carried aboard commercial aircraft. This had broad and immediate impact on the U.S. Postal Service, which has long depended on such flights to carry mail, particularly expedited services such as Priority and Express Mail. In fact, the USPS normally utilizes over 15,000 commercial flights daily to transport approximately one quarter of the daily mail volume-over 170 million pieces. In less than 3 hours on that September 11 in 2001, more than 4,500 commercial flights were landed immediately regardless of where they were or where they were headed. It was two days before mail began to move again aboard commercial aircraft, and restrictions persist 18 months later, including one prohibiting any mail weighing in excess of 16 ounces. It is this restriction in particular that most drastically affected movement of the mail. There are many measures that the USPS has identified and/or undertaken since the onset of the aforementioned situations. Some of these measures were permanent and some temporary. While the USPS is different in some respects from other businesses or organizations in general, there are certainly many parallels as well. In lights of this, there may be valuable lessons to be learned from the experiences and actions of the U.S. Postal Service. By studying these actions--and determining their effectiveness in terms of delivery standards, financial impact, and effect on short and long-term strategy--other organizations may ultimately save themselves time and money by following the example of the USPS. / by Christopher J. Hamel. / M.Eng.in Logistics