Thesis (S.M.)--Massachusetts Institute of Technology, System Design & Management Program, 2000. / Includes bibliographical references (leaves 130-132). / by Martin Busse. / S.M.

Thesis (S.M.)--Massachusetts Institute of Technology, System Design and Management Program, 2009. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 89-91). / The use of software in commercial aviation has expanded over the last two decades, moving from commercial passenger transport down into single-engine piston aircraft. The most comprehensive and recent official guidance on software certification guidelines was approved in 1992 as DO-178B, before the widespread use of object-oriented design and complex aircraft systems integration in general aviation (GA). The new technologies present problems not foreseen by the original guidance material and may complicate demonstration of compliance with such guidance material. The Federal Aviation Administration has deferred to industry experts in the form of the Radio Technical Commission for Aeronautics (RTCA) and the Society of Automotive Engineers (SAE) to create software and system approval guidance. The FAA's Advisory Circular (AC) 23.1309- 1C created a four-tier approval system to reduce software and system approval burden on smaller aircraft, creating a lower standard for small aircraft in the hopes that safety gains from technology would outweigh the potential cost of defects from less stringent requirements. Further guidance regarding the role of software in the overall system is spread across other documents including Aerospace Recommended Practice (ARP) 4754, ARP 4761, and applicable SAE Aerospace Standards (AS). The guidance material, spread across several documents, lacks sufficient specificity to be of use to an everyday practitioner. In addition the guidelines are not necessarily rigorously enforced when the same artifacts are required at different levels of design assurance as stated within DO-178B itself. / (cont.) After a literature review and regulatory analysis, this thesis investigates some example defects that escaped detection during application of the guidance in a real-world product, making specific recommendations to improve the guidance in a usable way. / by Ryan Erwin Berk. / S.M.

Thesis (S.M.)--Massachusetts Institute of Technology, System Design & Management Program, 2001. / Includes bibliographical references (p. 123-125). / This research explores what requirements are necessary for the development of a turbofan engine and how they evolve through the product development cycle. This work utilizes a parameter-based design structure matrix (DSM) to define the interfaces and interdependencies present in a large commercial aircraft propulsion system. The DSM was developed from the system level to the module level allowing one to examine the assumptions made throughout the entire life cycle of the product. The work utilizes the system-level DSM to show the similarities between the turbofan engine product development process (PDP) and the software spiral product development process. This work examines the parameter-based DSM in each of the design phases and attempts to understand the assumptions made in each phase and how the assumptions change as the product proceeds through the development cycle. By examination of the DSM, it was found that program goals and requirements lead to an initial set of design parameters. These design parameters are then iterated until a satisfactory product defamation is developed. Each stage concludes with the integration and testing of that stages work. In all stages risk management occurs and with the necessary revision of the program plan for subsequent stages (not in the system-level DSM). The work shows that the PDP for a turbofan engine can be viewed as a spiral process. The thesis then suggests that, in general, the current industry practices for the development of complex physical systems have similarity to the spiral framework for development of software. / by Douglas C. Hague. / S.M.

Thesis (S.M.)--Massachusetts Institute of Technology, System Design and Management Program, 2008. / Includes bibliographical references. / The general belief is that Location-Based Services (LBS) in emerging economies does not make much sense until there is widespread availability of geographic information system (GIS) data, broadband internet access, payment methods, infrastructure such as power, well developed advertising platform, etc. There is also the belief that these deficiencies make it next to impossible to realize revenues from the existing revenue models such as mobile adverts, online adverts, subscription, etc. This study shows how LBS services can be developed and deployed in emerging economies within these given set of constraints. It also adduces methods for overcoming some of the identified hindrances such as ways for creating effective and sufficient revenues from online and mobile adverts. The central hypothesis for this work is encapsulated in a "change of mindset" from developing products comparable to those in developed world (United States, Western Europe) to developing products which meet the immediate needs of the local environment in emerging economies/developing economies (however crude these solutions may appear initially from the POV of the developed world) and make use of not only locally available technologies but locally available phenomena. These solutions are then refined as they are consumed by the populace and the populace becomes more "sophisticated". This hypothesis is developed and fleshed out in a methodical manner using data and examples from developing countries - Nigeria (Africa), India (Asia), etc. This study finishes with the architecting of an LBS service (routing/navigation service) for an emerging economy using the framework developed in this study. Recommended future work includes developing more LBS services using this framework and deployment of the developed service, followed by a detailed analysis of the framework and possibly refinements to it. / by Ifeanyi Katchy. / S.M.

Thesis (S.M.)--Massachusetts Institute of Technology, System Design & Management Program, June 2001. / "May 2001." / Includes bibliographical references (p. 70-71). / by Hai The Truong. / S.M.

Thesis (S.M.)--Massachusetts Institute of Technology, System Design & Management Program, 2002. / Includes bibliographical references (leaves 103-104). / Supply chain management is one of the fundamental issues in the manufacturing and operation management. The performance of supply chain management directly affects an organization's overall performance. For the past several years, supply chain management has been a growing concern in modern manufacturing and business processes because of the complexity of products and new technologies. Especially, information technology and widespread usage of web-based systems are changing strategies of how companies manage their operations, supply chain structures and strategic alliances. A supply chain network by nature is a large and complex, engineering and management system. To understand its structure and to design effective policies, the internal dynamic behavior of the supply chain must be studied. System dynamics is an effective tool for understanding the structure and internal dynamic behaviors of a large and complex system. This thesis focuses on a supply chain problem at LSMC. Traditionally, LSMC is an engineering, technological and manufacturing driven company and its products have been dominant in the market for many years. For the past few years, however, the greater competition in the industry and the increasing pressures from the upstream and downstream of LSMC's supply chain have created interesting dynamic behaviors. The purpose of this thesis is to apply system dynamics methodology to LSMC's supply chain problem and potentially apply the framework of this thesis to general supply chain problems in other industries. The thesis includes various simulations and analyses to understand the problem. Especially eigenvalue elasticities approach provides significant insights, which deepen the understanding of the structure of the model and its dynamic behavior, and lead to the conclusion that the oscillatory behavior in the production inventories and in the demand for LSMC's products is an endogenous cause. / by Chalermmon Lertpattarapong. / S.M.

Thesis (S.M.)--Massachusetts Institute of Technology, System Design and Management Program, 2009. / Includes bibliographical references (leaves 67-69). / 'Cloud computing', is a broad concept and in general is a term used for internet-based computing resources that are in an unspecified remote location or locations and that are flexible and fungible. Clouds provide a wide range of computing capability available as a service where users are separated from the underlying technology by a set of APIs. These computing capabilities are made available by abstracting at different levels; at the hardware level, development platform or the applications level. Cloud computing is particularly helpful to application developers and IT operations because it allows them to focus on the service/application provided rather than worrying about scaling, failure, maintenance or reliability of these computing resources. By consolidating and sharing computing resources among multiple tenants thus improving utilization, cloud computing brings cost savings to end users. The higher the abstraction level, greater are the benefits resulting from better resource utilization and thus more cost savings, both for providers and end users. As computing resources become cheaper, network connectivity and bandwidth improve both in terms of availability and pricing and human resources becomes expensive, cloud computing is increasingly seen as viable replacement of enterprise owned local IT infrastructure. / (cont.) With the adoption of cloud computing comes a major shift in the underlying architecture of how we develop, deploy, deliver and run applications compared to existing behavior where we run applications on local computing resources and thus increasing pressure on enterprise software vendors to adopt these new business model for software development and new alternate software delivery models that are supported by and derive the benefits of cloud computing. While legacy enterprise software can simply be installed and run on instances on the cloud using cloud based infrastructure services, maximum benefits are realized by end users when these applications itself are provided as a service in the form of a platform or software. To do so, in most cases, legacy enterprise software would have to go through an architecture overhaul to be able to deliver existing functionalities as a platform or software as a service. Enterprise software vendors would also have to change their current business models where large license revenues, high maintenance cost of antiquated versions and heavily invested customers are the standard and move to pay-per-use cloud computing model. This thesis aims to study the implications of 'Cloud Computing' trends on the development, distribution, business models and the business of enterprise software vendors. This thesis tries to chart and predict the progress of trends in computing towards 'cloud computing', connect those trends to enterprise software usage changes and determine the impact on enterprise software vendors. / (cont.) This will help enterprise software vendors to determine what if any strategic options available will help adopt this technological innovation and conform to future enterprise software requirements based on this trend. / by Leonard Francis. / S.M.

Thesis (S.M.)--Massachusetts Institute of Technology, System Design & Management Program, 2001. / Includes bibliographical references (leaf 61). / by James M. Wang. / S.M.

Thesis (S.M.)--Massachusetts Institute of Technology, System Design & Management Program, February 2002. / "November 2001." / Includes bibliographical references (leaf 85). / by Adnan (Eddie) Khan. / S.M.

Thesis (S.M.)--Massachusetts Institute of Technology, System Design & Management Program, 2004. / Vita. / Includes bibliographical references (p. 98-99). / This thesis develops a numerical simulation environment as a management support tool applicable to the selection and scheduling of multiple, concurrent research and development projects under conditions of constrained resources and uncertain program requirements. A prototype version of this software tool, called SEMPRO (Simulation Environment for Multiple Project Resource Optimization), is developed to capture an operational model of the NASA Dryden Flight Research Center flight and a representative research project portfolio. An attribute-driven Work Breakdown Schedule generates resource-loaded activity networks for each entry in the research project portfolio. The project selection and project coordination problems are formulated as Binary Integer Linear Programming problems, as extensions of the traditional Resource Constrained Project Scheduling Problem (RCPSP). To alleviate the computational obstacles associated with these NP Hard problems, a Lagrange Relaxation formulation is used to generate a near-optimal, time-phased sequence for execution of the selected project activity networks. Stochastic, non-linear, discrete-event simulation dynamics are then employed to validate these linear optimization solutions against a representative model of the organization's research and development project operational processes. The SEMPRO prototype is written in the Microsoft Excel Visual Basic Application language to facilitate project management visualization and knowledge transfer. / by John Patrick Sharkey. / S.M.