Non Functional Testing - Definition, Examples & Test Cases

Testing is integral to the software development process. Each tech product should be assessed carefully for quality issues. This guarantees it meets functional and non functional features of the software. 

Such a scrutiny checks if the software matches all the key features and functionalities. Such a product has a greater chance of success when it is released in the market. Various tests are used to check different aspects of the application. They are classified into functional and non functional categories.

Previously, testing primarily focused on functional aspects of the product. Non functional features often didn’t get much attention during the initial evaluation phases. However, this has changed. We now see non functional testing getting its due prominence in enabling better customer satisfaction and retention.

This type of check is crucial for analyzing security and performance issues in detail. It makes sure that the application runs efficiently, even under heavy load conditions.

In this blog, I will cover the definition, examples, and cases of non functional testing.

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What is Non functional Testing?

This type of assessment examines aspects of an application, like- 

• Scalability

• Reliability

• Usability

• Security

• performance

• Compatibility

In simple terms, non functional testing leads to a higher quality product. It goes beyond merely having the right set of features. In my experience, non functional testing in software testing is as critical as functional testing. Without it, a system could function well in a controlled setting but fail in certain circumstances. Checking these aspects makes certain of successful adoption post its release.

Why Do You Need Non-functional Testing?

Functional and non functional testing is essential to new software. Functional testing checks if the software’s internal functions work accurately. And non functional testing checks how well the product performs in varying external conditions.

This type of scrutiny also covers the installation and execution of the software. It includes gathering metrics and measurements used for internal research and development.

Non functional testing in software testing gives a deep understanding of the product’s behavior and the technologies it uses. It helps mitigate production risks and related costs.

Objectives of Non Functional Testing

Here are some of the goals of this type of code verification-

• To reduce risks in production linked to non functional aspects.
• To enhance the product’s performance and security.
• To better understand the software’s behavior and the technologies used.
• To help lower costs related to non functional aspects of the application.

Different Types of Non functional Testing

We can classify this type of testing based on the type of behavior being assessed and the type of the software -

1. Stress Tests: This type of evaluation assesses how software behaves in unusual circumstances to find its breaking point.

You need to know how the framework responds under stress. Does it show the correct error messages? Does it fail totally? And if it does, how can it recover?

These tests help analysers study how the framework behaves during failures. This guarantees that the product can be recoverable and dependable.

2. Performance Tests: This testing approach checks how well the software functions. These tests can track issues in the software design and structure. This is usually done by-

• Finding failure points
• Estimating response times
• Identifying bottlenecks

This type of check tests verifies that the product is quick, adaptable, stable, and dependable.

3. Volume Tests: This is a distinct type of scrutiny that examines how well a framework performs when a lot of data is added to its database. It helps identify potential issues that might emerge with increasing data volumes. This type of assessment is also called flood testing.

You can use this form of evaluation to recognize data loss or storage issues while adding much data to the system.

Volume tests verifies that the software performs well to specific data volumes. This is significant for maintaining stability and performance.

4. Security test: This type of evaluation inspects software to uncover defects or weaknesses that could put data at risk. It aims to identify potential security threats. It also helps confirm that the product resists hacking or other security issues.

Typical security tests include-

• Ethical hacking
• Security scans
• Posture assessment
• Risk assessment
• Penetration testing

Carrying out these tests is pivotal for building a safe and reliable framework.

5. Upgrade and Installation Tests: This form of scrutiny ensures the software functions properly on all clients’ computers.

• Upgrade testing is for current clients.
• Installation testing is for new clients.

Both kinds of tests are crucial for client satisfaction. Regardless of how incredible your product is, if clients face issues during installation or upgrade, they won’t be able experience its maximum potential.

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Non Functional Testing Tools

There are many tools available for non functional testing. Here are a few of them. 

1. LoadRunner: LoadRunner is a powerful tool for non-functional testing. It verifies the app’s performance and load aspects. It simulates thousands of users concurrently accessing a system. This way, it assists the developers know more about bottlenecks and performance issues. You may use it to check response times and resource utilization. It is capable of assessing system behavior under various load conditions. This enables teams to optimize application performance and ensure scalability. They can easily validate system stability before deployment. 

2. vPerformer: Modern sites have numerous requirements for multiple reasons. Therefore, clients need a flexible application for testing. vPerformer is a famous tool for testing web performance. It permits clients to quickly assess both the functional and non functional aspects of a program without any problem.

3. JMeter: It is a perfect tool for dependability and automation testing in the market. It is free and commonly used to test web and FTP applications. Created by Apache, JMeter has a proven track record in its compatibility testing capabilities. It is broadly used to measure and analyze program performance.

Non functional Testing Parameters

These parameters act as a checklist for development teams to use. It ensures they test all the significant parts of the software product. Here is a list of the typical testing parameters.

1. Availability: With this parameter, a developer checks how easy is it for the customers to access the app without facing any downtime.

2. Security: This parameter ensures the software has the required security measures to shield client data from hackers.

3. Survivability: With this check, the development team measures how well the software can ensure business continuity in the case of server outage.

4. Reliability: Here, the experts verify the tech solution’s ability to work consistently and maintain steady performance under various load and stress conditions. 

5. Flexibility: This parameter measures an app’s ability to run on various devices with low-performance settings as-

• Low random access memory (RAM)
• Low-performing central processing unit (CPU)

Example Of Non Functional Testing

Here is the scenario of one of the non functional test cases.

A banking application is getting prepared for a major update. The development team is doing this type of test to be assured that the update runs as expected and is secure.

1. Usability Testing: Feedback from different clients is gathered to improve the application’s interface. This helps make it easy for everybody to use and comprehend.

2. Performance Testing: The app is tested to handle lots of users at once, during hectic times like holidays. This ensures transactions run smoothly.

3. Security Testing: The developers conduct stringent checks to see how the product copes with likely breaches and hack attempts. This makes sure that user data is safe from unauthorized access.

This non functional testing ensures that apps like banking software is safe and easy to use. It helps keeps customers satisfied and confident whenever there are new updates.

Functional Testing vs Non Functional Testing 

There’s a major debate about functional and non functional testing in the testing world. It tends to be challenging to say which is more vital, as both play a crucial role in successful tech product adoption. 

Functional testing checks if the software works as expected. And non functional testing checks how well it performs under various circumstances. Modern digital applications need both sorts to work well together.

Advantages of Non functional Testing

This type of evaluation provides multiple benefits-

• Improves user experience
• Enhance product security
• Provides stakeholders with accurate performance insights
• Optimizes system performance
• It requires less time overall than other testing methods
• Assesses readiness of new versions for production

Limitations of Non functional Testing

1. Pricey in case of software update: Developers conduct non functional testing to confirm that everything works accurately when software updates are made. This extra testing phase adds to the costs. It makes the product more costly overall.

2. Non functional tests are executed many times: Every time the application has some changes, these tests have to be done again. This type of examination of the product uses more resources.

Conclusion

Non functional testing is a smart strategy for generating the buzz around a viable tech product geared for long-term success. With it, the development team makes certain that the application functions well for clients and meets quality guidelines. Using this type of testing, developers can discover and resolve bugs early before releasing the software. This decreases the possibility of issues later. Plus, it also ensures that the customers get what they expect.

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FAQs

1. Is API testing non functional?

No, API testing is generally viewed as functional testing. It focuses on verifying the functionality and behavior of APIs as per their specification.

2. Is UI testing functional or nonfunctional?

UI checks are typically classified as functional testing. It guarantees that the user interface of an application behaves accurately according to its design and necessities.

3. What is functional testing and non functional testing in black box testing?

A. Functional Testing: In black box testing, functional testing confirms that the product functions as expected from the end client’s perspective.

B. Non functional Testing: Non functional testing in black box testing assesses aspects like performance and security.

4. Which are all non functional testing?

• Stress Tests

• Performance Tests

• Volume Tests

• Security test

5. Does QA do non functional testing?

Yes, Quality Assurance teams typically perform non functional testing alongside functional testing. It guarantees that the product works accurately and meets performance.

6. Which testing is an example of non functional testing?

Non functional testing includes performance testing. This checks how well a framework responds and stays stable while handling workload.

7. What is the scope of non functional testing?

The scope of non functional testing - 

• Finding where products need improvement in usability, stability, and more

• Making sure there are fewer chances of problems happening when end users start using the software. 

8. Why is non functional testing important?

Non functional testing is important because it ensures that the app meets key requirements like- 

• Usability
• Scalability
• Availability
• Security