| Quality - | (Software Engineering) the degree to which a product conforms to both explicit and implicit requirements |
| Quality function deployment (QFD) - | (Software Engineering) a technique that translates the needs of a customer in technical requirements for software by assessing the value of each requirement |
| Quality management - | (Software Engineering) a set of software engineering actions that helps ensure that software is built in a way that achieves high quality |
| Quality metrics - | (Software Engineering) measures of quality |
| Re-engineering - | (Software Engineering) a series of activities that transform legacy systems (with poor maintainability) into software that exhibits high quality |
| Reliability - | (Software Engineering) a measure of the degree to which software operates reliably over some period of time |
| Reusability - | (Software Engineering) the ability to reuse an already-existing program component in another application |
| Security - | (Software Engineering) the ability of software to operate in a manner that is secure from internal or external attack |
| Security testing - | (Software Engineering) testing tasks that probe the vulnerability of both client-side and server-side software |
| Six sigma - | (Software Engineering) a widely used strategy for statistical quality assurance |