Non-Functional Testing

Non-functional Testing is a type of software testing that is performed to verify the non-functional requirements of the application. It verifies whether the behaviour of the system is as per the requirement or not. It tests all the aspects that are not tested in functional testing.

Non-Functional Testing Defintion

Non-functional testing is a software testing technique that checks the non-functional attributes of the system. Non-functional testing is defined as a type of software testing to check non-functional aspects of a software application. It is designed to test the readiness of a system as per nonfunctional parameters which are never addressed by functional testing. Non-functional testing is as important as functional testing. 

Objectives of Non-functional Testing

The objectives of non-functional testing are:

• Increased usability: To increase usability, efficiency, maintainability, and portability of the product.
• Reduction in production risk: To help in the reduction of production risk related to non-functional aspects of the product.
• Cost Reduction: To help in the reduction of costs related to non-functional aspects of the product.
• Optimize installation: To optimize the installation, execution, and monitoring way of the product.
• Collect metrics: To collect and produce measurements and metrics for internal research and development.
• Enhance knowledge of product: To improve and enhance knowledge of the product behavior and technologies in use.

Non-Functional Testing Types and Techniques

Here is the Non-Functional Testing Techniques and Types mentioned bellow:

• Compatibility testing: is a type of testing to ensure that a software program or system is compatible with other software programs or systems. For example, in this, the tester checks that the software is compatible with other software, operating systems, etc.
• Compliance testing: is a type of testing to ensure that a software program or system meets a specific compliance standard, such as HIPAA or Sarbanes-Oxley. It is often the first type of testing that is performed when accessing the control environment.
• Endurance testing: is a type of testing to ensure that a software program or system can handle a long-term, continuous load. For example for the banking application, the application is tested to know if the system can sustain under the continuous expected load.
• Load testing: is a type of testing to ensure that a software program or system can handle a large number of users or transactions. For example, Running multiple applications on the computer simultaneously. 
• Performance testing: is a type of testing to ensure that a software program or system meets specific performance goals, such as response time or throughput. For example, organizations perform performance tests to identify performance-related bottlenecks.
• Recovery testing: is a type of testing to ensure that a software program or system can be recovered from a failure or data loss. For example, when the application is running and the computer is restarted, check the validity of the application's integrity.
• Security testing: is a type of testing to ensure that a software program or system is secure from unauthorized access or attack. For example, Organizations perform security testing to reveal flaws in the security mechanism of the information system.
• Scalability testing: is a type of testing to ensure that a software program or system can be scaled up or down to meet changing needs. For example, to measure the application's capability to scale up or scale out in terms of non-functional capability. 
• Stress testing: is a type of testing to ensure that a software program or system can handle an unusually high load. For example, extremely large numbers of concurrent users try to log into the application.
• Usability testing: is a type of testing to ensure that a software program or system is easy to use. For example, on the e-commerce website, it can be tested whether the users can easily locate the Buy Now button or not.
• Volume testing: is a type of testing to ensure that a software program or system can handle a large volume of data. For example, if the website is developed to handle traffic of 500 users, volume testing will whether the site is able to handle 500 users or not.
• Failover testing: is validates the system's capability to allocate sufficient resources toward recovery during a server failure.
• Portability testing: is testing the ease with which the application can be moved from one environment to another. 
• Reliability testing: is checks that the application can perform a failure-free operation for the specified period of time in the given environmental conditions.
• Documentation testing: is a type of software testing that involves testing the documented artifacts developed before or during the software testing process.
• Localization testing: is a type of software testing that is performed to verify the performance and quality of the software for a specific culture and to make the product look more natural for the foreign target audience.
• Internationalization testing: is a type of software testing that ensures the adaptability of software to different cultures and languages around the world accordingly without any modifications in source code.  

Non-functional Testing Parameters

Let's find some common non-functional testing parameters. These parameters are often used to ensure a system's performance, reliability, usability, and other quality attributes.

1. Security: This parameter is tested during Security testing. This parameter defines how the system is secure against sudden attacks from internal and external sources.
2. Reliability: This parameter is tested during Reliability testing. This defines the extent to which the system performs its intended functions without failure.
3. Survivability: This parameter is tested during Recovery testing. This parameter checks that the software system is able to recover itself in the case of failure and continuously performs the specified function without any failure.
4. Availability: This is tested during Stability testing. Availability here means the availability percentage of the software system to the original service level agreement. It means the degree to which the user can rely on the software during its operation.
5. Efficiency: This parameter means the extent to which the software system can handle the quantity and response time.
6. Integrity: This parameter measures how high the source code quality is when it is passed on to the QA.
7. Usability: This is tested in usability testing. This parameter means how easily usable the system is from the user's perspective.
8. Flexibility: This parameter means how well the system can respond to uncertainty in a way that allows it to function normally. 
9. Scalability: This parameter is tested during scalability testing. This parameter measures the degree to which the application can scale up or scale out its processing capacity to meet an increase in demand.
10. Reusability: This means how many existing assets can be reused in some form within the software product development process or in another application. 
11. Interoperability: This parameter is tested during the Interoperability testing. This checks that the application interfaces properly with its components or other application or software. 
12. Portability: This parameter checks the ease with which the software can be moved from one environment to another.

Benefits of Non-functional Testing

Here is the Non-functional testing advantages that enhance software quality and user satisfaction:

• Improved performance: Non-functional testing checks the performance of the system and determines the performance bottlenecks that can affect the performance.
• Less time-consuming: Non-functional testing is overall less time-consuming than the other testing process.
• Improves user experience: Non-functional testing like Usability testing checks how easily usable and user-friendly the software is for the users. Thus, focus on improving the overall user experience for the application.
• More secure product: As non-functional testing specifically includes security testing that checks the security bottlenecks of the application and how secure is the application against attacks from internal and external sources.

Limitations of Non-functional Testing

Here are the Non-functional testing dis-advantages:

• Non-functional tests are performed repeatedly: Whenever there is a change in the application, non-functional testing is performed again. Thus, it is more resource intensive.
• Expensive in case of software update: In case of software update, non-functional testing is performed again thus incurring extra charges to re-examine the software, and thus software becomes expensive.

Conclusion

Non-functional testing check that the software meets the requirement, security, and performance standards. While it improve the user experience and security, it can be want the resources and costly during updates. Overall, it is a crucial for delivering a reliable and easy development the software product.