401 |
Quantitative performance-based evaluation of a procedure for flexible design concept generationCardin, Michel-Alexandre, 1979- January 2011 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, 2011. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 152-163). / This thesis presents an experimental methodology for objective and quantitative design procedure evaluation based on anticipated lifecycle performance of design concepts, and a procedure for flexible design concept generation. The methodology complements existing evaluation methodologies by measuring anticipated performance via efficient computer modeling techniques. The procedure, in contrast to others, stimulates flexible design concept generation by packaging a short lecture on flexibility, and a prompting ideation mechanism. Controlled collaborative experiments had participants suggest alternative solutions to a design problem under different treatment conditions. Experimental conditions used the procedure for flexibility, while control conditions relied on prior training in science and engineering only, and free undirected ideation. Measures included the quantity of flexible design concepts generated, anticipated economic performance improvements compared to a benchmark design, participants' subjective impressions of satisfaction with the process and results, and results quality assessments. Seventy-one designers divided among twenty-six teams performed the experiments involving a simplified real estate infrastructure design problem. Application of the methodology demonstrated effective and efficient evaluation of the design procedure based on anticipated performance of design concepts. The lecture and prompting mechanism significantly improved anticipated performance compared to the benchmark design, by nearly thirty-six percent. The prompting mechanism significantly improved generation of valuable flexible design concepts. Lecturing improved significantly user satisfaction with the process and results, as well as results quality assessments. Even though prompting demonstrably improved anticipated performance and concept generation, it had no effect on participants' satisfaction with the process and results - unless combined with the lecture. Also, prompting did not lead participants to expect better results quality. This demonstrates the need for thorough and rigorous procedure evaluations based both on subjective user impressions and objective quantitative measurements. A preliminary analysis suggests that the proposed experimental platform can be used to study the influence of uncertainty and flexibility related words on discussion content, although more work is necessary to fully validate the approach. / by Michel-Alexandre Cardin. / Ph.D.
|
402 |
System design and the cost of architectural complexitySturtevant, Daniel Joseph January 2013 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, 2013. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 159-166). / Many modern systems are so large that no one truly understands how they work. It is well known in the engineering community that architectural patterns (including hierarchies, modules, and abstraction layers) should be used in design because they play an important role in controlling complexity. These patterns make a system easier to evolve and keep its separate portions within the bounds of human understanding so that distributed teams can operate independently while jointly fashioning a coherent whole. This study set out to measure the link between architectural complexity (the complexity that arises within a system due to a lack or breakdown of hierarchy or modularity) and a variety of costs incurred by a development organization. A study was conducted within a successful software firm. Measures of architectural complexity were taken from eight versions of their product using techniques recently developed by MacCormack, Baldwin, and Rusnak. Significant cost drivers including defect density, developer productivity, and staff turnover were measured as well. The link between cost and complexity was explored using a variety of statistical techniques. Within this research setting, we found that differences in architectural complexity could account for 50% drops in productivity, three-fold increases in defect density, and order-of-magnitude increases in staff turnover. Using the techniques developed in this thesis, it should be possible for firms to estimate the financial cost of their complexity by assigning a monetary value to the decreased productivity, increased defect density, and increased turnover it causes. As a result, it should be possible for firms to more accurately estimate the potential dollar-value of refactoring efforts aimed at improving architecture. / by Daniel J. Sturtevant. / Ph.D.
|
403 |
How should indicators be found for scenario monitoring ?He, Zheng, M. Eng. Massachusetts Institute of Technology 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. 76-78). / Scenario planning is a widely used approach for developing long-term strategies. The typical scenario process involves developing scenarios, identifying strategies whose success is contingent on the scenario, and monitoring the environment regularly to know which scenario(s) may become more likely. Hence it becomes necessary to find a way to monitor the business environment in order to inform the process of making strategic decisions under uncertainty. This thesis proposes to use a set of nested indicators to monitor environment. The approach consists of a seven-step process to build composite indicators and link them with scenarios. Individual indicators are selected based on intuitive theoretical frameworks. Different weights are assigned to individual indicators using factor analysis. And then composite indicators are built by linear aggregation of individual indicators. The composite indicators are used to assess the changes in the driving forces over time. Such changes serve as the basis for judging whether the level of the driving forces is high or low. Those levels are then used to infer which scenario is likely to come to pass. This thesis used a set of four scenarios to illustrate the application of the approach. Those scenarios were built for a chemical company's supply chain in Asian/Pacific region in 2025. The result suggested that the environment of the sub-region in the monitoring year was more like a "Collaborative World" or a mix of "Collaborative World" and "Demanding World". And it is more possible that the environment was evolving into those two scenarios instead of the others. / by Zheng He. / M.Eng.in Logistics
|
404 |
A decision-support model for managing the fuel inventory of a Panamanian generating companyPerez-Franco, Roberto, 1976- January 2004 (has links)
Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2004. / Includes bibliographical references (leaf 89). / Bahia Las Minas Corp (BLM) is a fuelpowered generating company in the Panamanian power system. The purpose of this thesis is to design and evaluate a decision-support model for managing the fuel inventory of this company. First, we research BLM and its fuel replenishment methods. Then we define the problem, its objective function, assumptions, parameters and constraints. After identifying the most important given information (fuel price forecast, demand forecast, and current inventory levels), we define the equations that relate these inputs with the order sizes, and the availability and reserve constraints. Due to the large number of constraints, we devise a mechanism to calculate lower limits for the aggregate order sizes that prevent violations of the constraints beyond user-defined limits. We prepare a model in Excel for use with a single fuel type. This model takes stochastic forecasts of demand and fuel prices, and determines the best size for the weekly fuel order. After testing the model under several different scenarios, we conclude that it responds correctly to changes in price and demand. The complete discussion of these results can be found in the body of the thesis. Finally, we present some recommendations for BLM, both in relation to this replenishment problem and to its supply chain in general. / by Roberto Perez-Franco. / M.Eng.in Logistics
|
405 |
Perspectives for logistics clusters development in RussiaTantsuyev, Andriy January 2012 (has links)
Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2012. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 63-66). / This thesis is a normative work aimed at identifying locations in Russia with high, medium and unclear potentials for logistics cluster development. As a framework this work uses four different models of logistics clusters: Major Seaport, Auxiliary Seaport, Major Inland and Auxiliary Inland logistics clusters. Conclusions are based on analysis of port connectivity, population incomes within eight hours of driving from a specific location, auto roads accessibility, economic effectiveness of local government and quality of auto roads. This paper provides guidelines for decision makers about how to set up the rail infrastructure in order to support the logistics development across different parts of Russia. Furthermore, this work suggests where future research should be amplified, especially concerning the quality of input data. / by Andriy Tantsuyev. / M.Eng.in Logistics
|
406 |
Building technological capability within satellite programs in developing countriesWood, Danielle Renee January 2012 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, 2012. / Vita. Cataloged from PDF version of thesis. / Includes bibliographical references. / Global participation in space activity is growing as satellite technology matures and spreads. Countries in Africa, Asia and Latin America are creating or reinvigorating national satellite programs. These countries are building local capability in space through technological learning. They sometimes pursue this via collaborative satellite development projects with foreign firms that provide training. This phenomenon of collaborative satellite development projects is poorly understood by researchers of technological learning and technology transfer. The approach has potential to facilitate learning, but there are also challenges due to misaligned incentives and the tacit nature of the technology. Perspectives from literature on Technological Learning, Technology Transfer, Complex Product Systems and Product Delivery provide useful but incomplete insight for decision makers in such projects. This work seeks a deeper understanding of capability building through collaborative technology projects by conceiving of the projects as complex, socio-technical systems with architectures. The architecture of a system is the assignment of form to execute a function along a series of dimensions. The research questions explore the architecture of collaborative satellite projects, the nature of capability building during such projects, and the relationship between architecture and capability building. The research design uses inductive, exploratory case studies to investigate six collaborative satellite development projects. Data collection harnesses international field work driven by interviews, observation, and documents. The data analysis develops structured narratives, architectural comparison and capability building assessment. The architectural comparison reveals substantial variation in project implementation, especially in the areas of project initiation, technical specifications of the satellite, training approaches and the supplier selection process. The individual capability building assessment shows that most trainee engineers gradually progressed from no experience with satellites through theoretical training to supervised experience; a minority achieved independent experience. At the organizational level, the emerging space organizations achieved high levels of autonomy in project definition and satellite operation, but they were dependent on foreign firms for satellite design, manufacture, test and launch. The case studies can be summarized by three archetypal projects defined as "Politically Pushed," "Structured," and "Risk Taking." Countries in the case studies tended to start in a Politically Pushed mode, and then moved into either Structured or Risk Taking mode. Decision makers in emerging satellite programs can use the results of this dissertation to consider the broad set of architectural options for capability building. Future work will continue to probe how specific architectural decisions impact capability building outcomes in satellite projects and other technologies. / by Danielle Renee Wood. / Ph.D.
|
407 |
A qualitative mapping and evaluation of an aerospace supply chain strategyHung, Jonathan (Jonathan W.), Pierce, Nicholas January 2011 (has links)
Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2011. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 55-56). / An effective supply chain is critical to the success of the products and services sold by companies. Companies must have an explicit understanding of what the supply chain strategy is in order to evaluate it. While most organizations have well-documented business strategies, they lack the same for their supply chain strategy. The methodology proposed by Perez-Franco, Singh, and Sheffi (201 1a; 201 1b) is a way to evaluate a supply chain strategy by using interviews, surveys, and discussions. The goal for this project was to test the applicability of the Perez-Franco et al. methodology to the aerospace industry through an applied case. We conducted a qualitative mapping of the supply chain strategy for a specific satellite program in Lockheed Martin Space Systems (LMSS). This thesis research is the first time the methodology has been applied and tested with a company in the aerospace industry. As a whole, LMSS has increased focus on their supply chain, and works to directly align their supply chain with their business objectives. For our case, we selected a specific project within the Space Systems division that lacks an explicitly stated supply chain strategy and has a potential gap with objectives. Through our research, we found that the Perez-Franco et al. methodology is applicable to the aerospace industry. As a result of this case application, we propose and present potential deviations and additions to build upon the methodology that yields interesting insights. The results with LMSS revealed areas of disagreement identified through evaluating themes of support, consistency, and sufficiency. Additionally, the methodology allowed us to conduct a diagnostic of the supply chain strategy against business goals. The primary conclusion in the diagnostic was a perceived conflict between quality and affordability initiatives. This is the key recommendation that the company should investigate further to locate the root cause(s) of the disagreement. Outcomes from this case show that the methodology can be applied to a wide number of industries. / by Jonathan Hung and Nicholas Pierce. / M.Eng.in Logistics
|
408 |
Knowledge integration for problem solving in the development of complex aerospace systemsHaddad, Marc George January 2008 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, 2008. / Includes bibliographical references (p. 238-248). / The development of complex products requires widespread knowledge interactions among a significant number of individuals and teams designing numerous interrelated components. Increasing product complexity typically leads to a corresponding increase in the types and sources of knowledge that need to be tapped during development, and a common strategy for managing product complexity is to outsource parts and components to external suppliers. As a result, the knowledge required for development is increasingly specialized and distributed across multiple boundaries spanning large-scale organizational networks, thus requiring the subsequent integration of this knowledge in order to accomplish the development task. A framework for knowledge integration in the development of complex systems in a large-scale organizational context is proposed in this thesis using an extensive review of the pertinent literature. The framework consists of the main channels, strategies, practices and mechanisms most commonly used to transfer, share and apply knowledge in the course of complex technical problem solving. The framework is progressively refined using empirical data collected through several rounds of interviews and a questionnaire instrument administered across three major aircraft programs in the defense aerospace industry. We find that knowledge integration in routine problem solving situations is most efficiently and effectively accomplished through extensive transfer and sharing of codified information using formal mechanisms such as information systems, while knowledge integration for major non-routine troubleshooting events requires extensive integration of individual expertise and know-how through both formal and informal advice sharing as well as direct assistance across internal and external organizational boundaries. / (cont.) A principal contribution of this research is in demonstrating how different characteristics of the engineering artifact defined in terms of product complexity, architecture and technology newness, and different aspects of problem solving including problem type and novelty, drive the knowledge integration process and the organizational system. We conclude that permeability of cross-program boundaries, direct relationships with functional groups and rich tacit knowledge flow from suppliers are critical for countering rampant firefighting in complex product development. / by Marc George Haddad. / Ph.D.
|
409 |
A decision support model for staffing supply chain planners : a case from the consumer packaged goods industryCastillo, Aura C. (Aura Carolina), Ucev, Ethem 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. 55-56). / Reducing or increasing labor force is not always effective when done without a thorough analysis. Organizations could face negative consequences such us unbalanced workload, inefficient procedures, lost sales, and negative work atmosphere. An increasing number of organizations are centralizing operations in order to optimize labor costs. However, not all companies assess the new number of employees required after centralization takes place, and for those companies that actually do this analysis, there are not quantitative tools, as far as we know in the literature, that can help them estimate the workforce required. This thesis project provides practitioners with a new mathematical model to estimate an appropriate number of production planners required for the supply chain planning department of a company in the consumer packaged goods industry. Using bivariate correlation and multiple regression analysis, we explored whether a relationship exists between the required number of production planners in the new centralized offices of the Company and 13 factors that impact employee's workload. The resulting regression model accounts for 98% of the variance of the number of planners. / by Aura C. Castillo and Ethem Ucev. / M.Eng.in Logistics
|
410 |
Absenteeism prediction and labor force optimization in rail dispatcher schedulingJensen, Taylor (Taylor Moroni), Sun, Qi 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 (pages 61-62). / Unplanned employee absences are estimated to account for a loss of 3% of scheduled labor hours. This can be costly in railroad dispatcher scheduling because every absence must be filled through overtime or a qualified extra dispatcher. One factor that complicates this problem is the uncertainty of unplanned employee absences. The ability to predict unplanned absences would facilitate effective scheduling of extra dispatchers and help reduce overtime costs. This thesis uses data from a railroad company over a four year period to examine company-wide factors thought to impact the number of unplanned absences among dispatchers. Using Poisson regression, we identify several factors that provide statistical evidence of influencing the number of unplanned absences. These factors are month, snowstorms, shift, and certain holidays. Despite these findings, the overall predictive capability of our regression model is very weak. Instead, we model the number of unplanned absences by shift as a Hadrom process with a Negative Binomial distribution and use Monte Carlo simulation to explore the impact on overtime costs of increasing the number of scheduled extra dispatchers and increasing the number of positions on which each employee is qualified to work. Our results show that increasing the number of extra dispatchers has a greater effect on reducing overtime, but the cost savings from reducing overtime expenses are not enough to offset the additional labor costs of having more employees on staff. Our results provide insight regarding the relationship among extra staff, higher levels of qualification among employees, and the willingness to use overtime in handling unplanned absences. / by Taylor Jensen and Qi Sun. / M. Eng. in Logistics
|
Page generated in 0.0914 seconds