NASA Space Rocket Logistics Challenges

The Space Launch System (SLS) is the new NASA heavy lift launch vehicle and is scheduled for its first mission in 2017. The goal of the first mission, which will be uncrewed, is to demonstrate the integrated system performance of the SLS rocket and spacecraft before a crewed flight in 2021. SLS has many of the same logistics challenges as any other large scale program. Common logistics concerns for SLS include integration of discreet programs geographically separated, multiple prime contractors with distinct and different goals, schedule pressures and funding constraints. However, SLS also faces unique challenges. The new program is a confluence of new hardware and heritage, with heritage hardware constituting seventy-five percent of the program. This unique approach to design makes logistics concerns such as commonality especially problematic. Additionally, a very low manifest rate of one flight every four years makes logistics comparatively expensive. That, along with the SLS architecture being developed using a block upgrade evolutionary approach, exacerbates long-range planning for supportability considerations. These common and unique logistics challenges must be clearly identified and tackled to allow SLS to have a successful program. This paper will address the common and unique challenges facing the SLS programs, along with the analysis and decisions the NASA Logistics engineers are making to mitigate the threats posed by each

Categorizing Non-Functional Requirements Using a Hierarchy in UML.

Non-functional requirements (NFRs) are a subset of requirements, the means by which software system developers and clients communicate about the functionality of the system to be built. This paper has three main parts: first, an overview of how non-functional requirements relate to software engineering is given, along with a survey of NFRs in the software engineering literature. Second, a collection of 161 NFRs is diagrammed using the Unified Modelling Language, forming a tool with which developers may more easily identify and write additional NFRs. Third, a lesson plan is presented, a learning module intended for an undergraduate software engineering curriculum. The results of presenting this learning module to a class in Spring, 2003 is presented

Automatic Acceptance Test Case Generation From Essential Use Cases

Requirements validation is a crucial process to determine whether client-stakeholders’ needs and expectations of a product are sufficiently correct and complete. Various requirements validation techniques have been used to evaluate the correctness and quality of requirements, but most of these techniques are tedious, expensive and time consuming. Accordingly, most project members are reluctant to invest their time and efforts in the requirements validation process.Moreover, automated tool supports that promote effective collaboration between the client-stakeholders and the engineers are still lacking. In this paper, we describe a novel approach that combines prototyping and test-based requirements techniques to improve the requirements validation process and promote better communication and collaboration between requirements engineers and clientstakeholders. To justify the potential of this prototype tool, we also present three types of evaluation conducted on the prototpye tool, which are the usability survey, 3-tool comparison analysis and expert reviews

Reactive Microservices - An Experiment

Os microserviços são geralmente adotados quando a escalabilidade e flexibilidade de uma aplicação são essenciais para o seu sucesso. Apesar disto, as dependências entre serviços transmitidos através de protocolos síncronos, resultam numa única falha que pode afetar múltiplos microserviços. A adoção da capacidade de resposta numa arquitetura baseada em microserviços, através da reatividade, pode facilitar e minimizar a proliferação de erros entre serviços e na comunicação entre eles, ao dar prioridade à capacidade de resposta e à resiliência de um serviço. Esta dissertação fornece uma visão geral do estado da arte dos microserviços reativos, estruturada através de um processo de mapeamento sistemático, onde são analisados os seus atributos de qualidade mais importantes, os seus erros mais comuns, as métricas mais adequadas para a sua avaliação, e as frameworks mais relevantes. Com a informação recolhida, é apresentado o valor deste trabalho, onde a decisão do projeto e a framework a utilizar são tomadas, através da técnica de preferência de ordem por semelhança com a solução ideal e o processo de hierarquia analítica, respetivamente. Em seguida, é realizada a análise e o desenho da solução, para o respetivo projeto, onde se destacam as alterações arquiteturais necessárias para o converter num projeto de microserviços reativo. Em seguida, descreve-se a implementação da solução, começando pela configuração do projeto necessária para agilizar o processo de desenvolvimento, seguida dos principais detalhes de implementação utilizados para assegurar a reatividade e como a framework apoia e simplifica a sua implementação, finalizada pela configuração das ferramentas de métricas no projeto para apoiar os testes e a avaliação da solução. Em seguida, a validação da solução é investigada e executada com base na abordagem Goals, Questions, Metrics (GQM), para estruturar a sua análise relativamente à manutenção, escalabilidade, desempenho, testabilidade, disponibilidade, monitorabilidade e segurança, finalizada pela conclusão do trabalho global realizado, onde são listadas as contribuições, ameaças à validade e possíveis trabalhos futuros.Microservices are generally adopted when the scalability and flexibility of an application are essential to its success. Despite this, dependencies between services transmitted through synchronous protocols result in one failure, potentially affecting multiple microservices. The adoption of responsiveness in a microservices-based architecture, through reactivity, can facilitate and minimize the proliferation of errors between services and in the communication between them by prioritizing the responsiveness and resilience of a service. This dissertation provides an overview of the reactive microservices state of the art, structured through a systematic mapping process, where its most important quality attributes, pitfalls, metrics, and most relevant frameworks are analysed. With the gathered information, the value of this work is presented, where the project and framework decision are made through the technique of order preference by similarity to the ideal solution and the analytic hierarchy process, respectively. Then, the analysis and design of the solution are idealized for the respective project, where the necessary architectural changes are highlighted to convert it to a reactive microservices project. Next, the solution implementation is described, starting with the necessary project setup to speed up the development process, followed by the key implementation details employed to ensure reactivity and how the framework streamlines its implementation, finalized by the metrics tools setup in the project to support the testing and evaluation of the solution. Then, the solution validation is traced and executed based on the Goals, Questions, Metrics (GQM) approach to structure its analysis regarding maintainability, scalability, performance, testability, availability, monitorability, and security, finalized by the conclusion of the overall work done, where the contributions, threats to validity and possible future work are listed

Pretrial Mediation of Complex Scientific Cases: A Proposal to Reduce Jury and Judicial Confusion

This Note proposes pretrial mediation using scientist-mediators for complex scientific disputes. Complex scientific disputes reflect the inherent tension between law and science. This tension results in dissatisfaction among judges, juries, and scientists because of the uncertainties embraced by science, but eschewed by law. Pretrial mediation would address some of these uncertainties before they are introduced into the courtroom. In short, the proposed pretrial mediation should reduce jury confusion and provide judges with guidance to assess the admissibility of scientific evidence and expert opinions by eliminating and clarifying scientific issues

System Qualities Ontology, Tradespace and Affordability (SQOTA) Project – Phase 4

This task was proposed and established as a result of a pair of 2012 workshops sponsored by the DoD Engineered Resilient Systems technology priority area and by the SERC. The workshops focused on how best to strengthen DoD’s capabilities in dealing with its systems’ non-functional requirements, often also called system qualities, properties, levels of service, and –ilities. The term –ilities was often used during the workshops, and became the title of the resulting SERC research task: “ilities Tradespace and Affordability Project (iTAP).” As the project progressed, the term “ilities” often became a source of confusion, as in “Do your results include considerations of safety, security, resilience, etc., which don’t have “ility” in their names?” Also, as our ontology, methods, processes, and tools became of interest across the DoD and across international and standards communities, we found that the term “System Qualities” was most often used. As a result, we are changing the name of the project to “System Qualities Ontology, Tradespace, and Affordability (SQOTA).” Some of this year’s university reports still refer to the project as “iTAP.”This material is based upon work supported, in whole or in part, by the U.S. Department of Defense through the Office of the Assistant of Defense for Research and Engineering (ASD(R&E)) under Contract HQ0034-13-D-0004.This material is based upon work supported, in whole or in part, by the U.S. Department of Defense through the Office of the Assistant of Defense for Research and Engineering (ASD(R&E)) under Contract HQ0034-13-D-0004

A Pluralism Worth Having: Feyerabend\u27s Well-Ordered Science

The goal of this dissertation is to reconstruct, critically evaluate, and apply the pluralism of Paul Feyerabend. I conclude by suggesting future points of contact between Feyerabend’s pluralism and topics of interest in contemporary philosophy of science. I begin, in Chapter 1, by reconstructing Feyerabend’s critical philosophy. I show how his published works from 1948 until 1970 show a remarkably consistent argumentative strategy which becomes more refined and general as Feyerabend’s thought matures. Specifically, I argue that Feyerabend develops a persuasive case against rationalism, or the thesis that there exist normative and exclusive rules of scientific rationality. In Chapter 2, I reconstruct Feyerabend’s pluralism and detail its relationship to his humanitarianism and epistemological anarchism. I understand Feyerabend’s pluralism as the combination of the principles of proliferation and tenacity. I show the evolution and justification of these principles from Feyerabend’s early papers until the late 1970s. In Chapter 3, I defend Feyerabend’s pluralism from its most prominent criticisms. I then clarify that Feyerabend’s pluralism amounts to a conception of the logic of theory pursuit and modify his view using insights from C.S. Peirce, Pierre Duhem, and Michael Polanyi. From Peirce, I show how economic, sociological, and value-laden features of theory pursuit may be used to constrain proliferation and tenacity. From Duhem and Polanyi, I try to show the proper role of tacit knowledge within a Feyerabendian framework. Finally, I show what implications Feyerabend’s pluralism has for models of distributing funds within scientific communities. I contend that it provides a more promising model that the ‘well-ordered science’ proposal advanced by numerous philosophers and social scientists. Specifically, I aim to understand what taking Feyerabend’s pluralism seriously entails for principles of balancing funding allocation decisions and the role of peer-review in evaluating the potential success of research proposals. I conclude by suggesting future lines of research for further analyzing and applying Feyerabend’s pluralism

Terence Hutchison's 1938 contribution to economic methodology

Terence Hutchison's 193 8 essay has been variously interpreted as introducing positivism, ultra-empiricism, and Popperian falsificationism into economics. Given Popper's well known anti-positivist stance, this state of affairs may seem puzzling. It might be presumed either that contradictions of some kind are involved in Hutchison's position, or that Popper's stance is not so far removed from logical positivism after all. In this thesis the latter option is adopted and Popper and logical positivism is viewed as part of a wider 'logical reconstructionist' pre-Quinean philosophy of science. Yet this move may not, and should not, resolve all disquietude on the part of the reader. For, to the extent that Hutchison adopted those aspects of Popper which clashed with logical positivism, there is an inherent contradiction between the view that Hutchison introduced positivism and the view that he introduced Popper into economics. This provides us with the springboard we need for our thesis. For the contradiction is resolved once these views are recognised as turning Hutchison into a straw man. In the weak version of our thesis we argue that there has been· an overemphasis on the positivist and Popperian elements in Hutchison's essay and a neglect of the extent to which it is concerned with economic methodology. In the strong version of our thesis we argue that Hutchison's essay is best viewed as a modem restatement of the inductivist-empirical-historical, as opposed to the deductivist-apriorist-formalist, approach in the long-standing methodenstreit in economics. In this restatement Hutchison draws on various elements of positivism and Popper to support a position that arises out of, and is specific to, the concerns of economic methodology, rather than to promote any particular philosophy of science in economics. Survey chapters on the philosophy of science with special emphasis on logical positivism, and on aspects of the history of economic methodology, enable us to evaluate the nature of Hutchison's essay and to substantiate our thesis. Thereafter we highlight the shortcomings of the traditional interpretations of Hutchison's essay pointing to how these have limited Hutchison's influence in economics.Economics and Management SciencesD. Litt. et Phil. (Economics

An improved requirement change management model for agile software development

Business requirements for software development projects are volatile and continuously need improvement. Hence, popularity of Agile methodology increases as it welcomes requirement changes during the Agile Software Development (ASD). However, existing models merely focus on change of functional requirements that are not adequate to achieve software sustainability and support change requirement processes. Therefore, this study proposes an improved Agile Requirement Change Management (ARCM) Model which provides a better support of non-functional requirement changes in ASD for achieving software sustainability. This study was carried out in four phases. Phase one is a theoretical study that examined the important issues and practices of requirement change in ASD. Then, in phase two, an exploratory study was conducted to investigate current practices of requirement changes in ASD. The study involved 137 software practitioners from Pakistan. While in phase three, the findings from the previous phases were used to construct the ARCM model. The model was constructed by adapting Plan-Do-Check-Act (PDCA) method which consists of four 4 stages. Every stage provides well-defined aims, processes, activities, and practices. Finally, the model was evaluated by using expert review and case study approaches. There were six experts involved to verify the model and two case studies which involved two software companies from Pakistan were carried out to validate the applicability of the proposed model. The study proposes the ARCM model that consists of three main components: sustainability characteristics for handling non-functional requirements, sustainability analysis method for performing impact and risk analysis and assessment mechanism of ARCM using Goal Question Metrics (GQM) method. The evaluation result shown that the ARCM Model gained software practitioners’ satisfaction and able to be executed in a real environment. From the theoretical perspective, this study introduces the ARCM Model that contributed to the field of Agile Requirement Management, as well as the empirical findings that focused on the current issues, challenges and practices of RCM. Moreover, the ARCM model provides a solution for handling the nonfunctional requirements changes in ASD. Consequently, these findings are beneficial to Agile software practitioners and researchers to ensure the software sustainability are fulfilled hence empowers the companies to improve their value delivery

Software Formal Inspections Guidebook

The Software Formal Inspections Guidebook is designed to support the inspection process of software developed by and for NASA. This document provides information on how to implement a recommended and proven method for conducting formal inspections of NASA software. This Guidebook is a companion document to NASA Standard 2202-93, Software Formal Inspections Standard, approved April 1993, which provides the rules, procedures, and specific requirements for conducting software formal inspections. Application of the Formal Inspections Standard is optional to NASA program or project management. In cases where program or project management decide to use the formal inspections method, this Guidebook provides additional information on how to establish and implement the process. The goal of the formal inspections process as documented in the above-mentioned Standard and this Guidebook is to provide a framework and model for an inspection process that will enable the detection and elimination of defects as early as possible in the software life cycle. An ancillary aspect of the formal inspection process incorporates the collection and analysis of inspection data to effect continual improvement in the inspection process and the quality of the software subjected to the process