Computers,design & Monsanto

The growth of the partnership between the engineer and computer is traced as seen from the perspective of engineers within a chemical company. First the elements in the partnership are discussed, then the nature of the computing environment within Monsanto Company is reviewed and finally some of the software that arose as a result of the interaction between the engineer and the computer in this environment is viewed.     

Feature-based assembly model for integration in computer-aided assembly

This paper proposes a real good approach for a computer-aided assembly (CAA) system, which makes use of software agent technology and deals with a representation of assembly features. The context of our work is the study of the engineering and manufacturing system based on the assembly features. The system never thinks like an assembly engineer, but makes it possible to support engineers in doing creative methodology, and producing new ideas better than the conventional CAA.     

Electronic nose for space program applications

The ability to monitor air contaminants in the shuttle and the International Space Station is important to ensure the health and safety of astronauts, and equipment integrity. Three specific space applications have been identified that would benefit from a chemical monitor: (a) organic contaminants in space cabin air; (b) hypergolic propellant contaminants in the shuttle airlock; (c) pre-combustion signature vapors from electrical fires. NASA at Kennedy Space Center (KSC) is assessing several commercial and developing electronic noses (E-noses) for these applications. A short series of tests identified those E-noses that exhibited sufficient sensitivity to the vapors of interest. Only two E-noses exhibited sufficient sensitivity for hypergolic fuels at the required levels, while several commercial E-noses showed sufficient sensitivity of common organic vapors. These E-noses were subjected to further tests to assess their ability to identify vapors. Development and testing of E-nose models using vendor supplied software packages correctly identified vapors with an accuracy of 70-90%. In-house software improvements increased the identification rates between 90 and 100%. Further software enhancements are under development. Details on the experimental setup, test protocols, and results on E-nose performance are presented in this paper along with special emphasis on specific software enhancements.     

Living the dream - an overview of the Mars exploration project

The twin Mars exploration rover vehicles began in early April 2000 as the dream of a young Jet Propulsion Laboratory (JPL) engineer. After two disappointing failures of the Mars Climate Orbiter and the Mars Polar Lander, NASA and the JPL were interested in determining a new course to invigorate the Mars Program. The objective of this article is to set out a chronology of the events of this exciting project in order to provide the context and background for the other articles. Within a month of the approval, the project was also asked to develop not one but two rovers, both to be sent during the same launch period to two distinct sites on Mars. Their ultimate goal was to study the history of water on Mars, in line with the basic Mars Program goal "to follow the water".     

An introduction to the NASA Shuttle ground operations simulator (SGOS)

The Shuttle ground operations simulator (SGOS) simulation software introduced in this paper is used to train NASA ground controllers and to certify launch countdown readiness. The SGOS executive and its subsystems have been an integral component of the Shuttle Launch Safety Program for almost 30 years. It is usable (via a LAN) by over 2000 NASA employees at the Kennedy Space Center and 11 000 contractors. SGOS supports over 800 models comprised of several hundred thousand lines of code and over 1000 Model Control Procedures. Copyright © 2007 John Wiley & Sons, Ltd.     

The benefits of posing application software as a language interpreter

Complicated and comprehensive software that is meant to execute in a non‐interactive or semi‐interactive mode needs to be configured to carry out the desired tasks, needs to carry out those tasks efficiently, needs to be extensible to take on additional ambitions, and needs to be maintainable. To reduce costs, it is helpful if experts in the discipline to which the program applies can configure and operate the program without needing to become expert software engineers and without needing to become familiar with the internal details of the program, and if software engineers who develop and maintain the program need not become experts in its target discipline. Progress toward these goals can be advanced by posing the software as a language interpreter. We describe the application of this principle to ground‐based data analysis software for the Microwave Limb Sounder instrument on the NASA Earth Observing System Aura satellite, but we believe the principle has substantially broader applicability. Copyright © 2007 John Wiley & Sons, Ltd.     

Optimizing Investments in Security Countermeasures: A Practical Tool for Fixed Budgets

As a software engineer or client, how much of your budget should you spend on software security mitigation for the applications and networks on which you depend? The authors introduce a novel way to optimize a combination of security countermeasures under fixed resources. Software engineers and their customers continuously face a complex and frustrating decision: given a fixed budget, which combination of vulnerability mitigation actions produces optimal system security? In a world without budgetary or temporal constraints, engineers could invest in whatever tools or training they deemed necessary to safeguard applications and networks. Or they could spend arbitrary amounts of time and money patching existing code and take painstaking precaution in writing new software to ensure its security. Of course, the economic reality is that software engineers are pushed to get their product to market as fast as possible, and security is often a distant priority in the face of budgetary constraints. However, fixing any remaining security vulnerabilities postproduction can be both costly and wasteful. In this article, we describe a novel methodology for quantitatively optimizing the blend of architectural and policy recommendations that engineers can apply to their products to maximize security under a fixed budget. The results of our optimization are sometimes surprising and even counterintuitive: bigger budgets don't always produce greater security, and the optimal combination of corrective actions changes nonlinearly with increasing expenditures. These findings suggest that some form of formal decision support could augment traditional methods.     

What can software engineers learn from manufacturing to improve software process and product?

The purpose of this paper is to provide the software engineer with tools from the field of manufacturing as an aid to improving software process and product quality. Process involves classical manufacturing methods, such as statistical quality control applied to product testing, which is designed to monitor and correct the process when the process yields product quality that fails to meet specifications. Product quality is measured by metrics, such as failure count occurring on software during testing. When the process and product quality are out of control, we show what remedial action to take to bring both the process and product under control. NASA Space Shuttle failure data are used to illustrate the process methods.     

基于SpringBoot的运载火箭信息交互指挥平台

为满足新一代运载火箭地面测发控系统通用化需求,减少平台研发、测试和维护成本,设计并实现了一种基于SpringBoot的运载火箭信息交互指挥平台,平台集成了信息交互、参数监测、数据判读及存储等功能,为指挥和判读人员提供了一种高效、便捷的工作方式;平台在满足业务需求的基础上,实现了软件自动化和国产化,减少了软件部署、移植的人工成本;经过试验表明该平台能够适应某系列运载火箭测发控系统的测试流程,实现了运载火箭地面数据的监测和判读,为测发控类软件一体化设计提供了一定的参考价值。     

Client–vendor knowledge transfer in IS offshore outsourcing: insights from a survey of Indian software engineers

We use knowledge‐based theory to develop and test a model of client–vendor knowledge transfer at the level of the individual offshore information systems engineer. We define knowledge transfer in this context in terms of mechanisms by which an offshore engineer employed by a vendor can (a) gain understanding of their onshore client; and (b) utilize their knowledge for the benefit of the client. Over large geographic, cultural and institutional distances, effective knowledge transfer is difficult to achieve, although it is central to the success of many offshore outsourcing contracts. Our empirical test consists of a survey of vendor software engineers physically located in India but working on development projects for clients in Europe and the United States. The findings support predictions regarding engineer exposure to explicit and tacit knowledge: We find client–vendor knowledge transfer to the offshore vendor engineer to be positively associated with formal training and client embedment. We also test whether an offshore vendor engineer's inappropriate reliance on informal discussions in the offshore location hinders effective client–vendor knowledge transfer. Our result for this is mixed. Finally, we show differences between offshore engineers who have had previous onshore experience and those who have not. Client embedment is a potent driver of knowledge transfer when the offshore engineer has had previous onshore placement, while it acts to reduce inappropriate reliance on informal discussions for those that have not had an onshore placement.     

What Do We Know about Developer Motivation?

Software engineers will do better work and stay with a company if they are motivated—as a result the success of software projects is likely to improve. The authors use the findings from their in-depth review of the 92 studies published in the last 25 years on software engineer motivation to give an overview of what managers need to know to improve motivation among their employees.     

Knowledge based quality system in support of space shuttle operations

In an attempt to use statistical variable data for process improvement at Kennedy Space Center (KSC), statistical quality control is being introduced in the shop floor for use by technicians and engineers. An Expert System is proposed to support this effort. The system has a component for process improvement, which uses a process capability index to suggest continuos process improvement to reduce cost and duration of the process.     

Establishing flight software reliability: testing,model checking,constraint-solving,monitoring and learning

In this paper we discuss the application of a range of techniques to the verification of mission-critical flight software at NASA’s Jet Propulsion Laboratory. For this type of application we want to achieve a higher level of confidence than can be achieved through standard software testing. Unfortunately, given the current state of the art, especially when efforts are constrained by the tight deadlines and resource limitations of a flight project, it is not feasible to produce a rigorous formal proof of correctness of even a well-specified stand-alone module such as a file system (much less more tightly coupled or difficult-to-specify modules). This means that we must look for a practical alternative in the area between traditional testing and proof, as we attempt to optimize rigor and coverage. The approaches we describe here are based on testing, model checking, constraint-solving, monitoring, and finite-state machine learning, in addition to static code analysis. The results we have obtained in the domain of file systems are encouraging, and suggest that for more complex properties of programs with complex data structures, it is possibly more beneficial to use constraint solvers to guide and analyze execution (i.e., as in testing, even if performed by a model checking tool) than to translate the program and property into a set of constraints, as in abstraction-based and bounded model checkers. Our experience with non-file-system flight software modules shows that methods even further removed from traditional static formal methods can be assisted by formal approaches, yet readily adopted by test engineers and software developers, even as the key problem shifts from test generation and selection to test evaluation.     

Faster, better, cheaper-NASA visualizes the solar system

Pathfinder is the first of many planned “Discovery Program” missions by NASA. The Discovery program is based on the concept of using “industry spacecraft” comprised of near commodity components built from generic parts that cost orders of magnitude less than the custom built equipment of earlier phases of space exploration. Daniel Goldin, administrator of NASA, has given his agency a mandate to explore the solar system faster, better, and cheaper than in the past. How do you build an “industry spacecraft”? First, use as much COTS (commercial off the shelf) hardware and software as possible. That eliminates the need for NASA to build every part and write all the software. Instead of building a custom computer, at a cost of millions, now NASA finds a commercial system (on Pathfinder, an IBM RS6000) and modifies it as needed. And the computer will probably run some version of a commercial operating system, saving thousands or millions more dollars in development costs. Other COTS components include the Motorola modem used to communicate between the rover and lander, and the real time operating system used in the lander. Second, make everything as small and light as possible. Launch costs-the cost of a rocket and fuel-still account for 30 to 40 percent of the total cost of a mission. Every gram of weight shaved off a payload reduces the cost of launch or adds to the number of scientific instruments that can go on board. Image processing equipment and methods used in Pathfinder are discussed     

A Survey of Software Engineering Practice: Tools, Methods, and Results

The results of a survey of software development practice are reported and analyzed. The problems encountered in various phases of the software life cycle are measured and correlated with characteristics of the responding installations. The use and acceptance of the term "software engineer" is investigated, and the functions and background of persons identified as software engineers are reported. The usage of a wide variety of software engineerilng tools and methods is measured; conclusions are drawn concerning the usefulness of these techniques.     

Software reflexion models: bridging the gap between design andimplementation

The artifacts constituting a software system often drift apart over time. We have developed the software reflexion model technique to help engineers perform various software engineering tasks by exploiting, rather than removing, the drift between design and implementation. More specifically, the technique helps an engineer compare artifacts by summarizing where one artifact (such as a design) is consistent with and inconsistent with another artifact (such as source). The technique can be applied to help a software engineer evolve a structural mental model of a system to the point that it is “good enough” to be used for reasoning about a task at hand. The software reflexion model technique has been applied to support a variety of tasks, including design conformance, change assessment, and an experimental reengineering of the million-lines-of-code Microsoft Excel product. We provide a formal characterization of the reflexion model technique, discuss practical aspects of the approach, relate experiences of applying the approach and tools, and place the technique into the context of related work     

浅析个体软件过程(PSP)

CMM被软件业界公认是当前最好的软件过程，PSP是CMM在软件工程师等级上的应用，是针对个人的软件过程的改进，文章介绍和分析了PSP的基本概念，作用；进化框架等内容，最后给出了PSP和CMM之间的联系。     

Body of knowledge for software quality measurement

Measuring quality is the key to developing high-quality software. The author describes two approaches that help to identify the body of knowledge software engineers need to achieve this goal. The first approach derives knowledge requirements from a set of issues identified during two standards efforts: the IEEE Std. 1061-1998 for a Software Quality Metrics Methodology and the American National Standard Recommended Practice for Software Reliability (ANSI/AIAA R-013-1992). The second approach ties these knowledge requirements to phases in the software development life cycle. Together, these approaches define a body of knowledge that shows software engineers why and when to measure quality. Focusing on the entire software development life cycle, rather than just the coding phase, gives software engineers the comprehensive knowledge they need to enhance software quality and supports early detection and resolution of quality problems. The integration of product and process measurements lets engineers assess the interactions between them throughout the life cycle. Software engineers can apply this body of knowledge as a guideline for incorporating quality measurement in their projects. Professional licensing and training programs will also find it useful     

Using metrics in management decision making

The amount of code in NASA systems has continued to grow over the past 30 years. This growth brings with it the increased risk of system failure caused by software. Thus, managing the risks inherent in software development and maintenance is becoming a highly visible and important field. The metrics effort within NASA's Mission Operations Directorate has helped managers and engineers better understand their processes and products. The toolkit helps ensure consistent data collection across projects and increases the number and types of analysis options available to project personnel. The decisions made on the basis of metrics analysis have helped project engineers make decisions about project and mission readiness by removing the inherent optimism of “engineering judgment”