Thesis (S.M.)--Massachusetts Institute of Technology, Engineering Systems Division, 2012. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 69-72). / Over the last fifty years, diffusion researchers have sought to explain why the rate of adoption of an innovation varies over time. Some innovations are adopted quickly as compared to others, which take decades for adoption. However, the rate of adoption of an innovation is observed to follow the 'S-curve'. Diffusion modeling is an approach to analyse the process of diffusion of innovation. Several diffusion models have been developed to predict the penetration curves while many other models are developed to explain the complexities of the underlying diffusion process. From the commercial perspective, diffusion modeling is of interest to managers because of its ability to predict sales of a product. Moreover, managers use diffusion models to chalk out strategies for successful product management. This thesis classifies the two diffusion modeling approaches: aggregate and individual. In aggregate modeling approach, the target market is aggregated and analyzed as a whole. Models are developed to forecast sales, analyze the effects of marketing efforts, examine the effects technology interactions, and study cross country diffusion. In individual modeling approach, diffusion is investigated at the consumer-level. The Models incorporate individual preferences in adoption decisions and study various effects of social structure and communication patterns. We analyze these models and discuss its strengths and weaknesses. Beyond this, we identify some of the unconquered problems of multi-product interactions and show the importance of diffusion modeling in this new frontier. / by Naveen Chandra Ranganath. / S.M.

Thesis (S.M.)--Massachusetts Institute of Technology, Engineering Systems Division, 2010. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 151-153). / The role of unmanned vehicles in military and commercial environments continues to expand, resulting in Shared Manned-Unmanned (SMU) domains. While the introduction of unmanned vehicles can have many benefits, humans operating within these environments must shift to high-level supervisory roles, which will require them to resolve system errors. Error resolution in current Human Supervisory Control (HSC) domains is performed using a checklist; the error is quickly identified, and then resolved using the steps outlined by the checklist. Background research into error resolution identified three attributes that impact the effectiveness of an error resolution checklist: domain predictability, sensor reliability, and time availability. These attributes were combined into a Checklist Attribute Model (CAM), demonstrating that HSC domains with high levels of complexity (e.g. SMU domains) are ill-suited to error resolution using traditional checklists. In particular, it was found that more support was required during such error identification, as data is uncertain and unreliable. A new error resolution checklist, termed the GUIDER (Graphical User Interface for Directed Error Recovery) Probabilistic Checklist, was developed to aid the human during the error identification process in SMU domains. Evaluation was performed through a human performance experiment requiring participants to resolve errors in a simulated SMU domain using the GUIDER Probabilistic Checklist and a traditional checklist tool. Thirty-six participants were recruited, and each was assigned to a single checklist tool condition. Participants completed three simulated error scenarios. The three scenarios had varying sensor reliability levels (low, medium, high) to gauge the impact of uncertainty on the usefulness of each checklist tool. The human performance experiment showed that the addition of error likelihood data using an intuitive visualization through the GUIDER Probabilistic Checklist improved error resolution in uncertain settings. In settings with high certainty, there was no difference found between the performances of the two checklists. While positive, further testing is required in more realistic settings to validate both the effectiveness of the GUIDER Probabilistic Checklist tool and the Checklist Attribute Model. / by Jacqueline M. Tappan. / S.M.

Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2012. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 50-51). / Humanitarian logistics encapsulates all supply chain efforts in response to a disaster or emergency. Despite the increased focus on humanitarian supply chains, there is not a general method for measuring the supply chain response capacity. We propose a model for humanitarian response capacity based on the stock levels and supplier capacity of an organization. We evaluate the model using inventory stock level data from the United Nations Humanitarian Response Depots (UN HRD) and a combination of inventory stock level and supplier contracted replenishment time data from the New York City Office of Emergency Management (NYC OEM). Model results in response to four simulated disaster events graphically show the approximate number of people that can be served as well as the oscillations in capacity during the response and replenishment phases. Given the span from global (UN HRD) to municipal (NYC OEM) contexts, this response capacity model provides a framework for developing a more general index that can aid organizations in making important investment decisions in order to save lives with more efficient disaster response. / by Ariahna N. Knight / 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. 66-67). / The WFP's transport of food aid to Ethiopia's landlocked population is constrained by supply chain bottlenecks at the port, and limited availability of trucks for inland transport. How can the WFP supply chain be optimized to effectively operate within the given constraints? First, we assess Ethiopia's current food transport capacity - a critical factor for the WFP's ability to deliver humanitarian food aid. Specifically, we review the current and forecasted movement of goods, gather and analyze information on transport capacity versus demand, and address the impact of government policies and regulations on the road transport sector. As a result, our research helps the WFP in analyzing quantitative and qualitative factors used in selecting routes and mitigating port bottleneck issues. The results of our study may be used by the WFP and other humanitarian organizations which aid distressed populations. / by Christina Sujin Kim and Javed Singha. / M.Eng.in Logistics

Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, 2012. / Cataloged from PDF version of thesis. / Includes bibliographical references. / Despite growing energy security and environmental concerns about dependence on oil as a transportation fuel, gasoline remains the overwhelmingly dominant fuel used by the US automotive fleet. Numerous previous efforts to introduce alternative fuel vehicles (AFVs) fueled by hydrogen, biofuels and electricity have failed, and significant barriers to a rapid transition to AFVs remain. One technology that has achieved considerable success in the US is the gasoline hybrid-electric vehicle (HEV), which integrate gasoline and electric powertrain components to significantly improve the efficiency of gasoline use. Since their introduction in 1999, over 2 million HEVs have been sold in the US, with more than 30 HEV models available to consumers today. In this dissertation I explore the dynamics of adoption of HEVs, examining factors influencing consumer adoption of HEVs to date, and, looking forward, the role of HEVs in the emerging market for plug-in electric vehicles (EVs). In Essay 1, I examine the market for the iconic Toyota Prius HEV. While more than 1 million Prius vehicles have been sold in the US, this market has been characterized by long wait lists at Toyota dealerships, evidence of supply constraints influencing the diffusion process. The innovation diffusion literature says relatively little about supply constraints, representing diffusion as a fundamentally demand-side process. Here I develop a model of innovation diffusion that incorporates production capacity and dealer inventory. Inclusion of supply constraints improves the explanatory power of the model in the Prius case, and demonstrates that the failure to model supply constraints can bias diffusion model parameter estimates. Essay 2 is motivated by the observation that Prius sales are not uniform geographically. Sales of the Prius have clustered in regions such as the West Coast, around Washington DC and through New England, with many fewer sales of the Prius in the south and mid-west. I propose two alternative hypotheses to explain the emergence of these clusters: 1) contagion through consumers' social networks; and 2) market heterogeneity that influences consumers' adoption thresholds. I develop a model of spatial innovation diffusion that captures spatial information generation between regions and consumer discrete choice between technologies. I find that in the Prius case, adoption clustering is explained by social contagion at the local level, which amplifies heterogeneous adoption thresholds. In Essay 3, I explore the future role of HEVs as a transitional technology in the emerging market for plug-in EVs, which hold the potential to achieve deep cuts in oil consumption and greenhouse gas emissions. The technology strategy literature suggests that hybrids technologies help the transition to radical technologies, accumulating producer learning, consumer familiarity and complementary assets that spillover to the radical technology. However, EVs remain expensive, have a limited electric range and lack a ubiquitous recharging infrastructure, while HEVs are relatively cheaper and refuel from the existing gasoline refueling infrastructure. I develop a model of hybrid and electric vehicle diffusion with multiple competing entrants, finding that the smooth transition from HEVs to EVs is possible but not assured, identifying public policy and firm strategy decisions that have the potential to accelerate this transition. / by David Ross Keith. / Ph.D.

Thesis (S.M.)--Massachusetts Institute of Technology, Engineering Systems Division, 2012. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 104-107). / A large percentage of companies implementing ERP experience schedule and budget overruns. In the two Air Force ERP projects studied in this thesis, DoD has experienced a schedule slippage of 3-4 years and life-cycle cost estimates almost doubled in each of these projects. Given the scale and complexity of these projects, and the number of different stakeholders involved, evaluation of the delay by checking off the high-level critical success factors as per literature does no good. Misaligned incentives between stakeholders especially sponsor organization and system integrator, failure to accommodate rework in the master project plan, choosing the right contract terms, lack of in-house technical expertise, control of sponsor over project execution were some of the aspects which emerged to be important during the case study analysis; and were re-validated using the system dynamics model. The impact of the different contract models on the Critical Success Factors, depending on the level of knowledge on legacy and the completeness of requirements, has also been examined. A System Dynamics model is developed to help in evaluating Lead System Integrator v/s Project management in-house governance models. We consider factors such as the sponsor's ability to adjust the RICE component estimations and the credibility of the contractor-staff working on the project. This thesis sets an outline for importance of governance models and delving deeper onto the process of selecting a contractor and setting incentives which help align the goals of the contractor to those of the sponsor organization. / by Farrah Tazyeen. / S.M.

Thesis: M. Eng. in Logistics, Massachusetts Institute of Technology, Engineering Systems Division, 2015. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 68-69). / This thesis focuses on a medical device manufacturer, DeCo, which offers surgical instruments to customers at no cost in order to facilitate the sale of implantable products that require the use of such instruments. DeCo is facing challenges in managing the supply chain for these outsourced instruments, such as long lead times, inaccurate forecasting, and excess inventory. Deco is interested in building a more responsive supply chain. To this end, our thesis investigated strategies to increase the supply chain agility by realizing opportunities in information flows, material movement, and channel alignment to achieve shorter lead time, lower inventory levels, and higher levels of service. We conducted interviews and analyzed forecast, inventory, and lead time data files to evaluate the company's supply chain agility in terms of key attributes such as: Inventory management, supply chain visibility, forecast, distribution channel management, supplier manufacturing flexibility, forecast, level of service, lead-time, and product lifecycle. Gaps between the current state and an agile supply chain were identified, and recommendations were made based on these weaknesses. Gaps in the supply chain were divided into three categories: information barriers, operational inflexibilities, and supply chain misalignments. Similarly, our recommendations were broken up into three main groups: Distributor strategies, supplier strategies, and DeCo's practices. By improving supply chain visibility, Deco can cut lead time to customers and significantly lower inventory. By gaining operational flexibility, DeCo can cut lead time from suppliers by 50%, avoid excess ordering due to minimum order quantity, and cut cost per unit. Key recommendations to achieve agility were to build a database of inventory at distributors' warehouses and implement a process to ship instruments between these warehouses; and to work with suppliers to build dedicated capacity on the production floor. / by Xinye Bai and Yaniv Rosenberg. / M. Eng. in Logistics

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