The Definitions

Software Assurance: The planned and systematic set of activities that ensure that software life cycle processes and products conform to requirements, standards, and procedures [IEEE 610.12 IEEE Standard Glossary of Software Engineering Terminology]. For NASA this includes the disciplines of Software Quality (functions of Software Quality Engineering, Software Quality Assurance, Software Quality Control), Software Safety, Software Reliability and Software Verification and Validation and Independent Verification and Validation.

Software Quality: The discipline of software quality is a planned and systematic set of activities to ensure quality is built into the software. It consists of software quality assurance, software quality control, and software quality engineering. As an attribute, software quality is (1) the degree to which a system, component, or process meets specified requirements. (2) The degree to which a system, component, or process meets customer or user needs or expectations [IEEE 610.12 IEEE Standard Glossary of Software Engineering Terminology].

Software Quality Assurance: The function of software quality that assures that the standards, processes, and procedures are appropriate for the project and are correctly implemented.

Software Quality Engineering: The function of software quality that assures that quality is built into the software by performing analyses, trade studies, and investigations on the requirements, design, code and verification processes and results to assure that reliability, maintainability, and other quality factors are met.

Software Reliability: The discipline of software assurance that 1) defines the requirements for software controlled system fault/failure detection, isolation, and recovery; 2) reviews the software development processes and products for software error prevention and/ or controlled change to reduced functionality states; and 3) defines the process for measuring and analyzing defects and defines/ derives the reliability and maintainability factors.


Software Safety: The discipline of software assurance that is a systematic approach to identifying, analyzing, tracking, mitigating and controlling software hazards and hazardous functions (data and commands) to ensure safe operation within a system.

Verification: Confirmation by examination and provision of objective evidence that specified requirements have been fulfilled [ISO/IEC 12207, Software life cycle processes]. In other words, verification ensures that “you built it right”.

Validation: Confirmation by examination and provision of objective evidence that the particular requirements for a specific intended use are fulfilled [ISO/IEC 12207, Software life cycle processes.] In other words, validation ensures that “you built the right thing”.

Independent Verification and Validation (IV&V): Verification and validation performed by an organization that is technically, managerially, and financially independent. IV&V, as a part of Software Assurance, plays a role in the overall NASA software risk mitigation strategy applied throughout the life cycle, to improve the safety and quality of software.