This post is part of a series on the Fundamentals of Software Testing. In this post, our author Alex explains the Software Testing Life Cycle and some different software testing methods.
In the Software development life cycle, we use different types of testing methods to examine and judge the performance of the software product or application. And in this article, we will focus on 5 main types of testing methods and delve into every single one to have a deeper understanding of the Huge Software Testing picture:
- Black box testing
- White box testing
- Agile testing
- Grey box testing
- Ad-hoc testing
1. Black Box Testing
Black box testing method is named so because in this method while testing the software tester cannot see the internal structure of the source code and program. While performing this test, tester just focuses on the inputs and the expected outputs without knowing how the application works and these inputs are processed. The purpose of this method is to check the functionality of the software to make sure that the software is working correctly according to the requirements and if it is meeting user demands.
This testing method can be applied to most of the software testing level: unit testing, system testing, integration testing and user acceptance testing.
- Knowledge of programming languages and implementation is not required, thus everyone can perform black box testing.
- Testers can work on black box tests in isolation, thus avoiding having a bias in favor of developer’s view. Furthermore, working on black box tests from tester’s point of view can help identify discrepancies in the specifications.
- It’s especially effective when using it on the large system.
- Test cases can be designed as soon as the functional specifications are done.
- It could be challenging to design the test case if the functional specifications are contradictory and vague.
- It’s impossible to identify all the inputs, thus having unidentified paths is inevitable.
- There is a high probability of repeating tests already performed by the programmer.
- Identifying tricky inputs could be difficult if the test cases are not developed based on specifications.
2. White Box Testing
In contrast with Black box testing, White box testing is a software testing method which tester can see the internal system code. White box testing is also known as Clear box testing, Glass box testing or Open box testing,… Unlike black box testing, White box testing requires testers to have knowledge of How the software is implemented and how it works, thus software developers are generally responsible for this process. This method can be applicable to all levels of testing but it is mainly used in unit testing and integration testing. The purpose of White box testing is enhancing security, the flow of inputs and outputs through the application, and improving design and usability.
- White box testing helps optimize the code by identifying hidden errors.
- Tests cases can be automated easily.
- Testing is more thorough as all code paths are usually covered.
- Testing can start early in Software development life cycle even if the graphical user interface is not available.
- White box testing can be quite costly and complex.
- Developers who usually execute white box test cases detest it. The white box testing by developers is not detailed can lead to production errors.
- It requires professional resources, with an in-depth knowledge of programming and implementation.
- It is time-consuming, especially the big applications.
3. Agile Testing
Agile Testing is a software testing practice that follows the principles of agile software development. In other words, agile testing means testing software for defects or any other issues quickly or within the context of agile and give quick feedback for better and faster development of the project.
Agile testing focuses on finding defects or any issues quickly or within the context of agile and then giving feedback to develop the project faster and better.
12 Principles Behind the Agile Manifesto:
- Our highest priority is to satisfy the customer through early and continuous delivery of valuable software.
- Welcome changing requirements, even late in development. Agile processes harness change for the customer’s competitive advantage.
- Deliver working software frequently, from a couple of weeks to a couple of months, with a preference to the shorter timescale.
- Business people and developers must work together daily throughout the project.
- Build projects around motivated individuals. Give them the environment and support they need, and trust them to get the job done.
- The most efficient and effective method of conveying information to and within a development team is face-to-face conversation.
- Working software is the primary measure of progress.
- Agile processes promote sustainable development. The sponsors, developers, and users should be able to maintain a constant pace indefinitely.
- Continuous attention to technical excellence and good design enhances agility.
- Simplicity–the art of maximizing the amount of work not done–is essential.
- The best architectures, requirements, and designs emerge from self-organizing teams.
- At regular intervals, the team reflects on how to become more effective, then tunes and adjusts its behavior accordingly.
- Saves time and money.
- Less Documentation.
- Regular feedback from the end user.
- Daily meetings can help to determine the issues well in advance.
- Working on detailed documents can take the test team a lot of time.
- As bug fixes and releases happen more often, more number of regression bugs may be introduced.
- Test team may not work on developing a consistent and powerful test system that can be maintained for years to come because of immediate test results that are expected from them.
4. Grey Box Testing
Grey box testing is a software testing method which is the combination of White box testing and Black box testing. In this method, the tester has partial knowledge of the internal structure and he or she will base on this knowledge to design test cases but test at the user, or black-box level. This method is mainly applicable Integration testing.
5. Ad-Hoc Testing
Ad hoc testing (or Monkey testing or Random testing) is a form of testing method which is performed without planning and documentation. The tests are conducted informally and randomly without any formal expected results.
This is the least formal method because the tester improvises the steps and arbitrarily executes them. Though defects found using this method are more difficult to reproduce (since there are no written test cases), this method is very important as it can help find important defects quickly which cannot be found by using formal methods.