Non Functional Testing in Software Testing

What is Non-Functional Testing?

Non-Functional Testing is one of the types of software testing which is used to check non-functional aspects of a software application. The major role of it is to test the performance of the system as per its parameters which must not be addressed by functional testing. It also comes under the black box testing technique.

In other hands, this testing can be easily understandable by checking how many people can simultaneously login into a software application. Both Functional Testing and Non-Functional Testing are important in Software Testing to get the expected output results.

Why You Need Non Functional Testing?

Non functional testing is just as critical as functional testing. And because teams need to conduct a mix of different types of testing, you need to be doing both.

Non functional testing makes applications more usable and more reliable. Unfortunately, it can often be rushed in an effort to meet release deadlines.

When non functional testing is overlooked, performance and UX defects can leave users with a bad experience and cause brand damage. Worse, applications could crash with an influx of users. Accessibility defects can result in compliance fines. And their security could be at risk.

Non-Functional Testing Working Process

Step 1

The process starts by implementing inputs to grow various factors. Factors include usability, portability and the efficiency of the program

Step 2

The testing plays a vital role in reducing the cost of the product. It also works to decrease the risk based on the response time and load test.

Step 3

The third step of the process includes a product or program optimization. Testers optimize the setup and execution process to increase user experience.

Step 4

The testing technique helps in providing metric calculations by collecting the data. The data provides information about internal research and development.

Step 5

The final step takes place to improve the behavior of the product. It enables user to enhance the product performance effectively.

Non-Functional Testing Tools

  • Forecast
  • JMeter
  • Load Complete
  • Loadrunner
  • Loadster
  • Loadstorm
  • Loadtracer
  • Neoload
  • Performer
  • WebLoad Professional
  • Webserver Stress Tool

Why use Non Functional testing tools

Non functional testing tools have evolved to a great extent because of demand in the market. Hence, there are both free and paid tools available online. It is important to check the right tool for the process before finalizing the program.

Every software will have both functional and non functional aspects. It is vital for testers to test both elements to enhance the performance of the program. Hence, engineers use Functional And Non Functional Testing together to offer a complete solution.

Types of non functional testing

1. Load testing

Load tests are a way of simulating demand on a software application and measuring the result. These tests are performed under expected demand and also in overload conditions (Spike testing).

To run these tests, the use of testing tools that simulate the load is required.

Load tests help identify the maximum operational capacity of an application, as well as in identifying bottlenecks and the causes of possible performance degradation.

When the test load rises above the expected parameters, these tests are known as stress tests.

2. Stress testing

They are load tests that are carried out with demands greater than the operational capacity, often until they reach the breaking point.

This type of software test is used to determine the stability of a system or application, with special attention to availability and error handling when faced with overload.

With stress tests, you can identify breakpoints, limits for safe use of the application, confirm design specifications, identify ways in which the system fails, among other aspects.

3. Configuration testing

Instead of testing the performance of an application from a load perspective, configuration tests are used to validate what performance effects certain configuration changes have to the application.

A typical example of this situation is to experiment with different load balancing methods and see the response of the application to similar levels of overload.

Another example is to verify if the system is able to function properly in different versions or configurations of hardware and software environments, such as various internet browsers, browser versions, among others.

4. Volume testing

The volume tests consist of validating the operation of the application with certain volumes of data.

The test subject is not limited to databases, it can also be used for example, to measure the performance of an interface when the interface file (a text file, XML, etc.) exceeds a certain size.

The objective is to see if given certain volumes of data the application works normally, what are the maximum limits of data volumes for the operation and identify fault conditions.

5. Usability testing

In usability tests, software testers focus on validating how easy an application is to use.

Features evaluated in usability include:

  • Ease of learning: How easy it is for users to perform basic functions the first time they use the application.
  • Efficiency: How quickly experienced users can perform their tasks.
  • Memorization: How easy to memorize the use of the application, that is, when a user spends a lot of time without using the application, he can remember enough to use it effectively next time, or he/she has to start learning again.
  • Errors: How many errors attributable to the design the user commits, how severe they are and how easy it is to recover from them.
  • Satisfaction: How much the user likes (or dislikes) the system.

6. Security testing

It consists of testing the security attributes or characteristics of the system,

  • Whether it is a secure system or not,
  • If it can be violated,
  • If there is access control through user accounts,
  • If these accesses can be violated.

The security tests also serve to validate whether the software development team has followed recommended security practices in its programming.

Among the security features of a system are confidentiality, integrity, authentication, authorization and availability.

7. Scalability testing

The scalability tests consist of verifying the ability of an application to scale any of its non-functional characteristics, such as the load it supports, number of transactions, data volumes, among others.

When designing scalability test cases, it is advisable to consider them in incremental blocks, given the difficulty of predicting the actual load that an application will have after being implemented in production.

8. Failover testing

Recovery tests are performed to verify how fast and how well an application recovers after experiencing hardware or software failure.

Therefore, to perform recovery tests it is necessary to force the failure and then verify if the recovery occurs properly.

9. Maintainability testing

Basically, it evaluates how easy it is to perform the maintenance of a system or application.

This means how easy it is to analyze, change and test these changes.

To perform this test, the way in which the application is implemented must be evaluated, following good software engineering practices.

That is, that recommended software engineering patterns are being followed and that anti-patterns are not inadvertently being introduced, that is, that common programming errors are not being made.

Advantages of Non Functional Testing

  • Part of the system can be tested functional while doing non functional testing.
  • Level of security increases many folds.
  • Helps to increase the performance.
  • Make sure that system is readily expected number of users.
  • Help to improve user experience

Disadvantages of Non Functional Testing

  • Each time system modified or upgraded non functional testing need to perform.
  • It may require various tools and may find this type of testing expensive.