QWE2000 Tutorial B2

Ms. Alice Lee and Dr. Eric Wong
(NASA Johnson Space Center and Telcordia Technologies)

"A Quantitative Risk Assessment Model For Software Quality, Testing and Safety"

Key Points

Presentation Abstract

The risk management model was created and validated by the instructor for NASA. The model was created to meet the challenge of the prevailing schedule/cost constraints without sacrificing product quality for highly safety-critical space flight software. The model, which has been applied to critical NASA flight software and ground test facilities, presents a quantitative approach to assessing the software's quality, test efficiency, and functional criticality. It can be used throughout the software development life cycle phases.

The model quantitatively measures the software down to the module level, and derives a risk index to present the module's risk level. The risk index provides a quick reference for project managers to understand the status of the software quality, so as to determine the budget and schedule more accurately prior to delivery. The risk index also provides the developers and testers with insight into where the problems are, and what causes the problems. With this approach, unnecessary testing was eliminated and test planning was more effective. The risk index along with the measurements of the composite elements served as a useful tool for managing schedule and budget risk and allowed the designers and testers to focus on improvement areas and mitigating risks. In addition, the application of the model can promote the Capability Maturity Level of the software to levels 4 and 5.

The assessment work is performed with automated tools. Part I of this seminar describes the concept, approach, and methodology of the risk model. The quality measurement tool will also be introduced in-depth. Part II of the seminar will discuss in detail a more efficient approach for software testing and maintenance.

About the Speaker

Alice Lee is currently the Chief Technologist for SR&QA (Safety Reliability and Quality Assurance) Office at NASA Johnson Space Center. She is also Assistant Division Chief for the Technology Division of SR&QA. She attended Purdue University, USA, for undergraduate studies in Computer Science. Received a Master's Degree in Computer Science from Rice University, USA, in 1986. She was also selected to attend MIT in 1994 under a NASA fellowship for Advanced Engineering Studies. She created this quantitative risk model for NASA.

Eric Wong is currently a Research Scientist at Telcordia Technologies (formerly known as Bellcore). He is one of the principal investigators at Telcordia responsible for developing a set of metrics for evaluating the overall quality of highly complex telecommunication systems and to identify their fault-prone software modules. He received his B.S. in Computer Science from Eastern Michigan University, and his M.S. and Ph.D. in Computer Science from Purdue University.