QOS

Typical service level requirements or quality of service of applications then were

1. Performance - What is the response time ?

2. Scalability  - can the application scale vertically and horizontally ?

3. Availability- Does the application have built in redundancy ?

4. Reliability  - Are the transactions maintain consistency and integrity like ACID ?

5. Maintainability  - Is code modular with small methods, right coupling/cohesion and sufficient
                                 documentaion ?

6. Manageabelity  - can the health of the system be monitored by tools provided  ?

7. Extensibility - Can we add functionality without impacting the system ? Does the code have concepts implemented like low coupling, interfaces and encapsulation ?

8. Security - Is the system secured and can handle security threats like Denial of Service by crashing or flooding ? Is the application able to maintain the confidentiality of the customers data ?