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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.
71

The complete bill of materials : a study in collaborative manufacturing

Hwu, Timothy Tingyaw, 1977- January 2003 (has links)
Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2003. / "June 2003." / Includes bibliographical references (p. 51). / The effects of the bill of material on outsourced manufacturing environment are studied by gathering information on costs to implement a new bill of materials (BOM) transfer process, the potential gains to maintaining a complete bill of material versus the partial or complete embedding of data, and surveying the high-tech electronics manufacturing industry's practice in communicating the bill to their partners. This thesis deals with a telecommunications products company fictitiously named Telcom and its contract manufacturing partners. While much of the cost involved is the price of implementing an Information Technology system to handle manufacturing collaboration, the heart of the issue is the management of the BOM data. Thus, the inclusion of the often undocumented cost or benefits of migration and ongoing coordination and support would further complicate the decision to implement. Furthermore, downstream efforts in supporting this process change and the manufacturer's interests in providing quality and timely service to their partners implies a need to transmit the fully detailed or "exploded" BOM. In some cases, the company's engineers were reluctant to express support for the exploded BOM due to the expected significant workload increase, the perceived added cost in maintaining extra part numbers, and the low expectation of returns for the endeavor. When approached by the prospect to receive standardized formatting but a partially embedded BOM however, the manufacturers expressed concerns regarding lead time elongation and quality degradation. The results on the comparison of the expected costs and benefits of implementation suggest a need for a delivery of a consistently formatted and complete bill of material. / by Timothy Tingyaw Hwu. / M.Eng.in Logistics
72

Evaluating inventory segmentation strategies for aftermarket service parts in heavy industry using linked discrete-event and Monte Carlo simulations

Bradley, Randolph L. (Randolph Lewis) January 2012 (has links)
Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2012. / Vita. Cataloged from PDF version of thesis. / Includes bibliographical references (p. 104-106). / Heavy industries operate equipment having a long life to generate revenue or perform a mission. These industries must invest in the specialized service parts needed to maintain their equipment, because unlike in other industries such as automotive, there is often no aftermarket supplier. If parts are not on the shelf when needed, equipment sits idle while replacements are manufactured. Stock levels are often set to achieve an off-the-shelf fill rate goal using commercial inventory optimization tools, while supply chain performance is instead measured against a speed of service metric such as order fulfillment lead time, the time from order placement to customer receipt. When some parts are more important than others, and shipping delays are accounted for, there is ostensibly little correlation between these two metrics and setting stock levels devolves into an inefficient and expensive guessing game. This thesis resolves the disconnect between stock levels and service metrics performance by linking an existing discrete-event simulation of warehouse operations to a new Monte Carlo demand categorization and metrics simulation, predicting tomorrow's supply chain performance from today's logistics data. The insights gained here through evaluating an industry representative dataset apply generally to supply chains for aftermarket service parts. The simulation predicts that the stocking policy recommended by a simple strategy for inventory segmentation for consumable parts will not achieve the desired service metrics. An internal review board that meets monthly, and a quarterly customer acquisition policy, each degrade performance by imposing a periodic review policy on stock levels developed assuming a continuous review policy. This thesis compares the simple strategy to a sophisticated strategy for inventory segmentation, using simulation to demonstrate that with the latter, metrics can be achieved in one year, inventory investment lowered 20%, and buys for parts in low annual usage categories automated. / by Randolph L. Bradley. / M.Eng.in Logistics
73

Multi-echelon inventory optimization for fresh produce

Limvorasak, Saran, Xu, Zhiheng January 2013 (has links)
Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2013. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 69). / For fresh produce, the product freshness is a key value to end consumers. Retailers try to maximize product freshness at retail stores while maintaining high product availability. Fresh produce that is close to the end of its life cycle will either be scrapped or be sold at a much lower price. With an increasing demand volatility and complication of supply chain network, obsolescence cost from these spoilages has been increasing recently. Our research focuses on the study of multi-echelon inventory optimization for fresh produce. We investigated the impacts of an additional fulfillment center in a supply chain to justify an improvement in product freshness. We analyzed three relevant factors: transit time, inventory dwell time and safety time, which affect the time products spend in a supply chain from the suppliers to the retail stores. Our objective was to create a predictive model that could determine whether product freshness could be improved when those products are shipped through a supply chain network with an additional fulfillment center. While a fulfillment center increases the total transit time by adding more "touches" of the inventory, it can provide benefits by reducing demand variability through the risk pooling effect. When an fulfillment center aggregates demand from several grocery distribution centers, it pools the demand volatility across various locations, thus reducing the demand volatility and the safety stock. Our model demonstrated that, with a fulfillment center, six product categories (Berries, Watermelons, Cherries, Mixed melons, Stone fruit, and Strawberries) had a decrease in the safety time that is more than the increase in total transit time, resulting in the improved product freshness at retail stores. Further, we defined a term "Enhance Coefficient of Variation (ECV)" to quantify the demand volatility. Finally, we determined a set of minimum ECV ratios in order to make an fulfillment center benefits the product freshness under different replenishment frequencies. Retailers can use this ECV ratio as an indicator to make channeling decisions. / by Saran Limvorasak and Zhiheng Xu. / M.Eng.in Logistics
74

Data-driven risk assessment for truckload service providers

Chittella, Sriram Kishore, Machado Teixeira, Marcos January 2015 (has links)
Thesis: M. Eng. in Logistics, Massachusetts Institute of Technology, Engineering Systems Division, 2015. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 78-79). / Non-asset backed third-party logistics companies provide shippers access to a flexible source of capacity through transportation carrier spot market. The increased volatility in the trucking spot market rates is turning the 3PL businesses more risky and complex. To maximize profitability, a better understanding of the risk and the volatility patterns across the different geographies, time periods and other factors are investigated based on three years of real spot market data from a major 3PL company in US. Throughout this research we investigate the nature of trucking spot market volatility to allow truckload service providers to reduce their risk when setting long-term contracts. Using three different measures of volatility we are able to assess the company's risk profile and arise with insights to improve truckload service providers' business. / by Sriram Kishore Chittella and Marcos Machado Teixeira. / M. Eng. in Logistics
75

Effect of auditory peripheral displays on unmanned aerial vehicle operator performance

Graham, Hudson D January 2008 (has links)
Thesis (S.M.)--Massachusetts Institute of Technology, Engineering Systems Division, 2008. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Includes bibliographical references (p. 101-105). / With advanced autonomy, Unmanned Aerial Vehicle (UAV) operations will likely be conducted by single operators controlling multiple UAVs. As operator attention is divided across multiple supervisory tasks, there is a need to support the operator's awareness of the state of the tasks for safe and effective task management. This research explores enhancing audio cues of UAV interfaces for this futuristic control of multiple UAVs by a single operator. This thesis specifically assesses the value of continuous and discrete audio cues as indicators of course-deviations or late-arrivals to targets for UAV missions with single and multiple UAVs. In particular, this thesis addresses two questions: (1) when compared with discrete audio, does continuous audio better aid human supervision of UAV operations, and (2) is the effectiveness of the discrete or continuous audio support dependent on operator workload? An experiment was carried out on the Multiple Autonomous Unmanned Vehicle Experiment (MAUVE) test bed with 44 military participants. Specifically, two continuous audio alerts were mapped to two human supervisory tasks within MAUVE. These continuous alerts were tested against single beep discrete alerts. The results show that the use of the continuous audio alerts enhances a single operator's performance in monitoring single and multiple, semi-autonomous vehicles. The results also emphasize the necessity to properly integrate the continuous audio with other auditory alarms and visual representations in a display, as it is possible for discrete audio alerts to be masked by continuous audio, leaving operators reliant on the visual aspects of the display. / by Hudson D. Graham. / S.M.
76

Modeling learning when alternative technologies are learning & resource constrained : cases In semiconductor & advanced automotive manufacturing

Rand-Nash, Thomas January 2012 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, 2012. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 173-179). / When making technology choice decisions, firms must consider technology costs over time. In many industries, technology costs have been shown to decrease over time due to (a) improvements in production efficiency and the accumulation of worker experience accompanying production, known as "learning-by-doing," and (b) firm investments in research and development, worker training and other process improvement activities, known as "learning-by-investing." Rapid technological progress may mean that new technologies become available while existing technologies still exhibit learning-related cost reductions. In these cases, switching to a new technology means giving up these ongoing benefits while also incurring new technology introduction costs. Additionally, In some industries, high switching costs, regulatory compliance and/or the risks associated with new technologies may require firms to continue allocating production volume and investments to an existing technology whether or not a new technology is introduced. In these cases, firms must decide how to allocate finite production volume and investment resources between technologies. Learning is driven by resource allocation. Therefore, sharing finite resources among multiple learning technologies may reduce the learning-related benefits associated with each. This may lead firms to underestimate technology costs, leading to sub-optimal technology choice and resource allocation decisions. A methodology is presented which couples technology costs over time via capacity and investment resource allocation to characterize the impacts of (1) learning in an incumbent technology, and (2) resource allocation constraints, on technology choice and resource allocation decisions. Case studies in the semiconductor and automotive industries are examined using this method in combination with process based cost modeling. We find that (1) when the existing technology is still learning, diverting resources to a new technology results in an opportunity cost in both technologies which diminishes the benefits of switching technologies; (2) this effect can persist over a wide range of learning rates and technology costs; (3) capacity allocation constraints can significantly change the conditions under which the firm should choose a new technology, and (4) cumulative production volume and investment based learning differentially impact technology costs, leading to different cost-minimizing resource allocation decisions. / by Thomas Rand-Nash. / Ph.D.
77

Meeting the RFID mandate : options for Wal-Mart suppliers and evaluation methodology / Meeting the Radio Frequency Identification mandate

Singh, Kapil Dev, 1975- January 2004 (has links)
Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2004. / Includes bibliographical references. / Various retailers like Wal-Mart, Target, and Albertsons have announced their mandates asking their top suppliers to become RFID enabled beginning 2005. Meeting the mandate has become a sort of cost of doing business with Wal-Mart for suppliers. The objective of this thesis is to look for ways of meeting the mandate and preventing it from just becoming a cost of doing business with Wal-Mart. The thesis explores the various options available to suppliers and identifies the cost and benefit associated with each option and develops an evaluation methodology for the various options. / by Kapil Dev Singh. / M.Eng.in Logistics
78

Performance measurement and signaling in the humanitarian marketplace

Marcil, Thomas Henry January 2013 (has links)
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. 191-198). / This thesis considers ways in which humanitarian organizations can evaluate their performance internally, signal their performance to others, and what this might mean for the humanitarian relief community as a whole. Part I demonstrates an approach by which humanitarian organizations can develop key performance indicators (KPIs) to measure the performance of their logistics and supply chain activities, using a nonprofit specializing in the provision of medical relief as a case study. This thesis argues that a system of KPIs developed and analyzed by the organization can help improve operational performance, establish goals, and guide strategy. Part II then examines high-level organizational trends in the United States international relief sector, and questions whether contemporary literature on such trends find support in data from the Internal Revenue Service (IRS). This thesis argues that the humanitarian "market" today exists in a newly competitive state defined by this paper as "response-leadership." The humanitarian sector thus mirrors concentrated for-profit markets that embody the price-leadership model. This thesis finally suggests governmental and institutional policies concerning performance measurement that, given the competitive nature of the humanitarian marketplace defined in Part II, may improve market mechanisms in this sector. / by Thomas Henry Marcil. / S.M.in Technology and Policy
79

Measuring supply chain carbon efficiency : a carbon label framework

Craig, Anthony (Anthony J.) January 2012 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, 2012. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 273-293). / In the near term, efficiency improvements represent a key option for reducing the impacts of climate change. The growing awareness of climate change has increased the attention regarding the carbon emissions "embedded" in the products we consume. This increased attention creates a need to measure and improve the carbon efficiency of the supply chains that produce those goods. In this thesis we present a method for measuring the carbon efficiency of a supply chain that recognizes the decentralized nature of supply chains. First, drawing from concepts in supply chain performance measurement and eco-efficiency we propose a definition of supply chain carbon efficiency that is consistent with the idea of a product's carbon footprint. We present Life Cycle Assessment (LCA), a method for quantifying the environmental impact of a product or service, as the appropriate method of measuring a product's carbon footprint and demonstrate the use of LCA through a case study involving the supply chain of bananas. Next, we characterize the difficulty and uncertainty in performing an LCA of a supply chain through an analysis of our case study of bananas. We present a framework to reduce the uncertainty though the concept of a carbon label. The carbon label provides a system where firms can measure the carbon footprint of their activities and share this information with their supply chain partners. We identify the role of third parties in facilitating information sharing and define the characteristics that describe the carbon label. Finally, we demonstrate how the carbon label works in the context of the supply chain. Through an analysis of the mode and carrier assignment steps in an integrated supply chain we develop new metrics that show how sharing information can increase the accuracy of the measured carbon footprint and improve decision-making. We provide incentive for firms to share information through the development of a vertical differentiation model of product carbon labels. Our model shows how consumer demand for lower carbon products drives reductions in the carbon footprint throughout the supply chain and induces firms to voluntarily disclose their carbon footprint. / by Anthony J. Craig. / Ph.D.
80

Development of a comprehensive supply chain performance measurement system : a case study in the grocery retail industry

Chou, Chih-Fen, 1976- January 2004 (has links)
Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2004. / "June 2004." / Includes bibliographical references (leaves 87-88). / While companies are looking for a single solution or a set of metrics that they can apply to measure their supply chain performance, it is clear that such a single solution does not exist. An effective supply chain performance measurement system has to align with a company's own supply chain processes. This thesis, based on the research of several established performance measurement models including the Balanced Scorecard and the SCOR Model, provides a framework for companies to build their supply chain performance measurement systems in-house. This thesis recommends a roadmap consisting of eight steps for companies to follow in the design and implementation phases of establishing a supply chain measurement system. The result is a set of 21 performance metrics is proposed that can be used by a company in the grocery retail industry to measure the efficiency of its supply chain. This metric set is well balanced because it encompasses six different criteria: comprehensive, causally oriented, vertically integrated, horizontally integrated, internally comparable, and useful. In conclusion, it is critical for companies from different industries to custom-tailor their own set of performance metrics, based on a careful evaluation of their individual business processes and supply chain performance objectives, that will allow management to do a better job utilizing existing capital resources and planning for strategic change and business development. / by Chih-Fen (Amy) Chou. / M.Eng.in Logistics

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