1. Functional Suitability 功能的适用性
   System provides functions that meet stated or implied needs
2. Reliability 可靠性
   System can maintain a specified level of performance when used under specified conditions.
3. Security  安全
   Protection of system items from accidental or malicious access, use, modification,destruction, or disclousurce.
4. Maintainability 可维护性
   System can be modified, corrected, adapted or improved due to changes in environment or requirements.
5. Performance Effciency 性能效率
   System provides appropriate performance, realted to the amount of resouces used.
6. Operability 可操作性
   System can be understood, learned, used and is attractive to users.
7. Compatibility 兼容性
   Two or more systems can exchange information while sharing the same environment.
8. Transferability 可转移性
   System can be transferred from one environment to another.