Being trustworthy or performing consistently well.
Capability of a product to perform specified functions under specified conditions for a specified period of time without interruptions and failures.
Note: Wear does not occur in software. Limitations in reliability are due to results from faults in requirements, design and implementation, or from contextual changes.”
Typical Acceptance Criteria
- Time or time interval when the system shall be available
- Availability percentage
- Time to detect a fault
- Time to repair a fault
- Time or time interval in which the system may operate in degraded mode
- Proportion (e.g. 99%) or rate (e.g. up to 42 per second) of a certain class or types of faults that the system either prevents or handles without failing
Source: Bass et al., 2021, p. 75
What Stakeholders mean by reliable
Stakeholder | (potential) Expectation for reliable |
---|---|
User | * available when need it * produces expected results * offers expected functionality * user documentation is reliable |
Product-Owner | * realiably add new functions and features * reliable estimates concerning effort for changes * reliable at runtime, available when users need it |
Management | * cost and effort of development, operations and support are reliably predictable * reliable with respect to operations, especially security and interoperability |
Developer | * reliably add new features or functions to the system without unwanted side-effects. * realiably predict the effects of changes to the system |
Tester | test results are reliable (as in consistent or repeatable) |
Admin | * reliably start, configure and monitor the system * reliable release and update processes |
Domain-Expert | - |
Others | * technical documentation is reliable (current and correct) |
Qualities tagged with #reliable
- Accuracy
- Availability
- Backward compatibility
- Capacity
- Clarity
- Compatibility
- Compliance
- Correctness
- Dependability
- Fail safe
- Fault isolation
- Fault tolerance
- Faultlessness
- Functional appropriateness
- Functional completeness
- Functional correctness
- Functional suitability
- Functionality
- Graceful degradation
- Hazard warning
- Immunity
- Longevity
- Operational constraint
- Preciseness
- Precision
- Predictability
- Recoverability
- Reliability
- Resilience
- Risk identification
- Robustness
- Safe integration
- Safety
- Security
- Stability
- Standard Compliance
- Suitability
- Traceability
- Vulnerability
Requirements tagged with #reliable
- Available 7x24 with 99% uptime
- Availability
- Operability
- Reliability
- User error protection
- Avoid common vulnerabilities
- Vulnerability
- Detect inconsistent user input
- Consistency
- Usability
- User assistance
- User experience
- Fast and accurate sensor
- Accuracy
- Efficiency
- Preciseness
- Good code readability score
- Code Readability
- Legibility
- Readability
- New Features Introduce No Bugs
- Changeability
- Predictability
- Reliability
- Precise calculation of gamma coefficient
- Accuracy
- Correctness
- Preciseness
- Reliability
- Restored to fully functional state 12h after complete failure
- Availability
- Mean time to recovery
- Operability
- Reliability
- Server fails, system continues to operate without downtime
- Availability
- Fault tolerance
- Reliability
- Stability
- Severe errors are detected and the system shuts down into safe state
- Dependability
- Operability
- Reliability
- Safety
- System can run >12h without re-booting the operating system
- Availability
- Mean time between failures
- Reliability
- Stability