In Non-Functional Testing, the software components or system are tested against its quality characteristics. Non-functional here, mainly refers to the software aspects that may not be related to a particular function or user action, for instance scalability, security, etc. Moreover, similar to functional testing, non-functional testing is also performed at all levels.
Types of Non-Functional Testing
There are many different types of Non-functional testing and these include
Reliability Testing – It is a type of non-functional testing in which the software is exercised in order to detect failures and remove them before the software is finally launched in the market. The main objective of performing Reliability Testing is to determine the product reliability and to ensure whether the software developed meets the customer’s reliability requirements.
Usability Testing – In this mode of testing, the testers test the software product for its ease of use, i.e. they test to ensure that the software’s user interface is as simple as intended. The main objective of performing Usability Testing is to validate whether the software developed is user-friendly or not.
There are mainly five components of Usability Testing, they are
- Learnability – This answers the question to how easy it is for the users to learn accomplishing basic tasks the first time they start using the software design
- Efficiency – This type of usability testing is performed to prove how fast and efficient the software works and answers the question to how long does an experienced user take to accomplish the tasks using the software
- Memorability – This type of usability testing checks on the aspects of user’s memory, i.e. to prove whether the user remembers the design of the software after not using it for a long time or does the user have to start all over again to learn everything regarding the use of the software
- Errors – This is done to check how many errors does a user make and how sever are these errors. Also, this mode of testing is performed to see how easily the users recover from the errors they make and how long does it take them to do so
- Satisfaction – It answers the question of how much the users like using the particular system or software
Efficiency Testing – The aim of the efficiency testing is to test the amount of code and testing resources that are required by the program to complete a particular task. It is measured by Software Test Efficiency, which is defined as the number of test cases executed, divided by unit time (usually per hour).
Maintainability Testing – This form of non-functional testing is basically performed to define how easy it is to maintain the system or software. It mainly aims to define how easy it is to analyse, change and test the application or software product.
Portability Testing – This type of non-functional testing refers to the process of testing the ease with which the software product can be shifted from one environment to another. For instance, consider moving of an application from Windows 2000 to Windows XP. Portability is usually measured in terms of time required to move the software and to complete the documentation updates.
Baseline Testing – Baseline Testing basically refers to validating documents and specifications depending on which the test cases will be designed. The validation of requirement specifications is known as baseline testing.
Compliance Testing – This type of testing is mainly related to the IT standards followed by the company or organization developing the software and it is done to find if there are any deviations from the company’s prescribed standards
Documentation Testing – It is done according to the IEEE documentation which mainly describes plans for, or results of, testing a system or its component. The various types of documentation testing includes test case specification, test incident report, test log, test plan, test procedure, and test report. Therefore, testing of all these documents is basically known as documentation testing.
Endurance Testing – Endurance testing of software is usually done by testing a system with a significant load extended over a significant period of time. This main objective here is to find out how the system behaves in a condition of sustained use. For instance, during software testing of a system, it may behave exactly as expected when tested for a particular amount of time, say 1 hour. But when the system is tested for an extended period of time, say 3 hours, it may exhibit problems like memory leaks, causing the system to fail or behave completely randomly.
Load Testing – This form of testing is performed to observe the behavior of the software when subjected to a specific load. It is performed to observe and record the behaviour of the system under both, normal and at peak conditions. Load Testing is greatly helpful in determining the maximum operating capacity of the software along with any bottlenecks that prevent the system from reaching its maximum potential. Moreover, through load testing, elements which are causing the degradation of the software can also be determined. For instance, if the number of users is increased, then how much CPU and memory of the system will be consumed.
Performance Testing – Performance Testing is one of the most important non-functional testing types and is performed to determine how fast the system works regarding some of its aspects when put under a particular workload. There are many uses of performance testing, like it can show that the system meets performance specifications or criteria, or it can compare two systems to determine which one performs better than the other, or else it can also measure which parts of the system are responsible for causing the system to perform negatively.
Compatibility Testing – It is basically done to test whether the application or software developed is compatible with the working environment or not. The software is checked if it is compatible with the particular hardware, operating system, database or other system software it is designed to work with.
Security Testing – This is done to check if the software developed is secure enough or not. Anyone can try and hack the system hence it is completely necessary to have a secured software so that if any sensitive information is stored, it should be safe. In this process, the security weaknesses of the software are tested and improved, so that hackers are unable to hack into the system.
Scalability Testing – In this testing process, the software is tested to measure its minimum and maximum capabilities of any of its non-functional attributes like load supported, the number of transactions system can handle at once, the data volume that can be stored, etc.
Volume Testing – Volume Testing is done to test the software or application for storing a certain amount of data. For instance, consider a volume test of an application is conducted with a specific data size. Here, the goal maybe to expand the database to that size and then test the application’s performance with that amount of data on it.
Stress Testing – Stress Testing is usually conducted to test the software’s performance out of its operational limit, normally to observe the results for further studies and using them to improve the software in its upcoming versions. It is also used to determine the stability of the software developed. It is mostly focused on validating robustness, availability, and error handling under a heavy load, rather than focusing on what would the ideal performance of the system be under normal circumstances. There could be many reasons to conduct stress testing of software applications, which also includes making sure that the software does not crash under heavy conditions or in cases of insufficient computational resources, like low memory or disk space.
Recovery Testing – Recovery Testing is a testing process that is done to check how fast the system can recover itself after going through any type of crash, hardware failure, system corruption, etc. In recovery testing, the system is forced to fail in a variety of ways to verify the speed and technique of properly recovering the system again. For instance, consider a software system that is receiving data from a network. Here, unplug the connecting cable in the middle of the process and then plug the cable back after a while. Then analyse how fast the application recovers itself and continues to receive data from the point at which the connection was lost. One can also test an internet browser by restarting the system while there are many tabs open within the browser, and then check how fast the browser is able to recover all the tabs again or if it can recover at all.
Internationalizing Testing and Localization Testing – Internationalization of the software basically refers to designing the software or application in a way that it can be adapted to various languages and regions around the world without any functional changes. On the other hand, localization of the software is a process in which the internationalized software is adopted for a specific region or language by adding specific local components and translating texts.