Engineering Papers⌕ Search

Engineering topics

Hall, Dana

Publications and source records attributed to Hall, Dana.

A proven approach for more effective software development and maintenance

Modern space flight mission operations and associated ground data systems are increasingly dependent upon reliable, quality software. Critical functions such as command load preparation, health and status monitoring, communications link scheduling and conflict resolution, and transparent gateway protocol conversion are routinely performed by software. Given budget constraints and the ever increasing capabilities of processor technology, the next generation of control centers and data systems will be even more dependent upon software across all aspects of performance. A key challenge now is to implement improved engineering, management, and assurance processes for the development and maintenance of that software; processes that cost less, yield higher quality products, and that self-correct for continual improvement evolution. The NASA Goddard Space Flight Center has a unique experience base that can be readily tapped to help solve the software challenge. Over the past eighteen years, the Software Engineering Laboratory within the code 500 Flight Dynamics Division has evolved a software development and maintenance methodology that accommodates the unique characteristics of an organization while optimizing and continually improving the organization's software capabilities. This methodology relies upon measurement, analysis, and feedback much analogous to that of control loop systems. It is an approach with a time-tested track record proven through repeated applications across a broad range of operational software development and maintenance projects. This paper describes the software improvement methodology employed by the Software Engineering Laboratory, and how it has been exploited within the Flight Dynamics Division with GSFC Code 500. Examples of specific improvement in the software itself and its processes are presented to illustrate the effectiveness of the methodology. Finally, the initial findings are given when this methodology was applied across the mission operations and ground data systems software domains throughout Code 500.

Pajerski, Rose↗

Profile of NASA software engineering: Lessons learned from building the baseline

It is critically important in any improvement activity to first understand the organization's current status, strengths, and weaknesses and, only after that understanding is achieved, examine and implement promising improvements. This fundamental rule is certainly true for an organization seeking to further its software viability and effectiveness. This paper addresses the role of the organizational process baseline in a software improvement effort and the lessons we learned assembling such an understanding for NASA overall and for the NASA Goddard Space Flight Center in particular. We discuss important, core data that must be captured and contrast that with our experience in actually finding such information. Our baselining efforts have evolved into a set of data gathering, analysis, and crosschecking techniques and information presentation formats that may prove useful to others seeking to establish similar baselines for their organization.

Hall, Dana↗

The role of software engineering in the space station program

Software engineering applications snapshots within the Space Station Freedom Program; software engineering and Ada training; software reuse; hierarchial command and control; program characteristics; integrated, international environments; software production, integration, and management; and integrated simulation environment are outlined in viewgraph format.

Hall, Dana↗

Measuring the impact of computer resource quality on the software development process and product

The availability and quality of computer resources during the software development process was speculated to have measurable, significant impact on the efficiency of the development process and the quality of the resulting product. Environment components such as the types of tools, machine responsiveness, and quantity of direct access storage may play a major role in the effort to produce the product and in its subsequent quality as measured by factors such as reliability and ease of maintenance. During the past six years, the NASA Goddard Space Flight Center has conducted experiments with software projects in an attempt to better understand the impact of software development methodologies, environments, and general technologies on the software process and product. Data was extracted and examined from nearly 50 software development projects. All were related to support of satellite flight dynamics ground-based computations. The relationship between computer resources and the software development process and product as exemplified by the subject NASA data was examined. Based upon the results, a number of computer resource-related implications are provided.

Mcgarry, Frank↗