What are different Service level requirements (SLRs) ?

Service level requirements (SLRs) also called as : 

• Non-functional requirements
• Software Quality Attributes
• xabilities or ilities

LIST OF SLRs
1. Performance

• Response Time

2. Scalability

• Increasing load without changing the system
• Types : 
• Vertical Scalability
• Horizontal Scalability

3. Reliability

• Integrity
• Consistency

4. Availability

• System is always accessible

5. Extensibility

• Add / modify functionalities without impacting existing system functionalities

6. Maintainability

• Ability to correct flaws in the existing functionality without impacting other components of the system

7. Manageability

• Ability to manage the system to ensure the continued health of a system with respect to scalability, reliability, availability, performance, and security
• Monitoring of the QoS requirements and the ability to change the system configuration to improve the QoS dynamically without changing the system

9. Security

• Ability to ensure that the system cannot be compromised
• Key concepts : 
• Integrity
• Availability
• Confidentially
• Non-repudiation