Importance of Non — Functional Testing
Introduction
Testing is an important part of software development process which helps to ensure customer satisfaction. This article describes the impotency of conducting non functional testing before release any software to the customer.
Non-functional testing refers to the testing of those aspects of a software application which are not connected in any way with a defined user action or a function.
As the name suggests, it concentrates on an application’s non-functional aspects such as performance, usability, security, compatibility, and all other aspects that are not tested under functional testing.
Non-functional testing is performed to verify these NFRs and if the system’s behavior is in accordance with them.
Factors can be considered under Non-Functional Testing
The following are some of the significant non-functional aspects of an application that are considered and tested under non-functional testing:
- How does the application behave and perform under normal circumstances?
- How does it behave when a large number of users log in simultaneously?
- How much stress could the application handle?
- How secure is the application?
- Is the application robust enough to recover from a disaster?
- Does the application show similar behavioral patterns in a different environment or OS?
- Are the documents accompanying the application easy to understand?
- The singular purpose of NFR testing is to ensure that the application works well with regards to the non-functional aspects.
- Ultimately, the motive of non-functional testing is to test all characteristics of an application that would help to provide an application which meets the business expectations.
The importance of Non — Functional Testing
- Consider an application that is developed and wholly tested for functional requirements, but non-functional testing is not performed. Now imagine what would happen when the application goes live and is immediately subjected to a massive load.
- In the absence of non-functional testing, you would be very unsure of the application’s ability to handle massive traffic. The application may become slow or even crash in the worst case scenario. What an embarrassment that would be! In another scenario, imagine if the application is not tested for security, if that is the case then an unauthorized party could easily crack the data entered by the app users.
- Non-functional testing is as important as functional testing. It ensures security and establishes the reliability of the application. It ensures that the application developed is robust enough to work under duress.
- The application’s compatibility with various devices, its user-friendliness, its endurance and a host of other vital parameters are established and verified through NFR testing.
Types of Non- Functional Testing
Among the many variants of NFR testing, the following are the most important non-functional testing types.
Performance Testing
Performance testing is done to evaluate the system’s overall performance. The process involves measuring the response time of the system as a whole and that of the crucial app elements as well.
This test may be conducted as a part of integration tests or even system testing.
Load Testing
Load testing is one of the most important non-functional testing types. It is done to evaluate the system’s performance under normal conditions.
The normal usage scenario is repeated with a large number of users to determine the consistency of app response times.
Load testing helps to ascertain the system’s ability to handle the sustained pressure of multiple users logging in concurrently.
Make sure that you conduct the test on a dedicated server which creates a simulation of the actual environment and that the database is realistic.
Stress Testing
Stress testing is done to assess how the system reacts when it is pulled beyond its capabilities.
The difference between stress testing and load testing is that only the maximum allowable load is generated in load testing whereas the load generated in stress testing is beyond what you expect the system to handle.
This test helps to evaluate if the system performs along expected lines when it is low on resources.
Security Testing
One of the most crucial non-functional testing types, security testing is undertaken to ensure that there are security loopholes in the application for data thieves to explore.
It goes a long way in negating the threats of data thefts. Confidentiality, integrity, authentication, and authorization are the main areas tested under this type of non-functional testing.
Compatibility Testing
Compatibility testing allows you to verify if the application is compatible with different browsers, devices, and operating systems; all at vastly different strengths of configuration.
Localization Testing
Localization testing verifies the application in different locales (and hence in different languages).
The primary focus is on testing the content and GUI of the application and ascertaining if it is ideal for a particular locale.
Usability Testing
Simply put, usability testing measures the user-friendliness of the application’s interface.
When you test GUI, usability testing becomes particularly important. It also evaluates error reportage and error diagnosis.
Scalability Testing
Scalability testing verifies the application’s ability to handle increased traffic, a spike in the data volume, or an increase in the number of transactions.
The system must work as expected when these parameters are increased.
Example Non Functional Testing check list for mobile application / web application
