Software testing: methods, pitfalls and tips

Software testing has become an indispensable process step in the production and programming of software products in order to ensure the quality, reliability and security of software products.
As an essential part of the software development lifecycle, software testing plays a crucial role in identifying and fixing bugs before software is delivered to the end user.
In this article, we take a closer look at the topic of software testing and share with you the experience we have gained in over 15 years of software testing in-house and in IT outsourcing.

What is software testing?

Software testing is the evaluation of a software application to ensure that the application meets the requirements specified (by the customer) and is free of errors.
This process usually involves running the software in a controlled environment to identify and fix bugs or defects and expose usability deficiencies.

What are the different forms of software testing?

In the field of software testing, there are a variety of approaches that differ according to various criteria such as the degree of automation, the focus of the test or the time of execution in the development cycle.
Two of the most basic categories are manual testing and automated testing, both of which play essential roles in the testing process.
However, there are other, more specific types of tests that can be used depending on the project requirements.

• Manual tests

Manual testing is the most traditional form of software testing, in which test cases are carried out by a human tester without the use of automated tools.
This method is particularly suitable for exploratory tests, usability tests or other scenarios where human judgment and flexibility are required.
The advantage of manual testing is the tester’s ability to intuitively recognize unexpected behaviors or appearances of the software that automated testing might miss.
Manual tests are predestined for IT outsourcing, the processing according to previously defined rules, which nevertheless requires additional requirements compared to automation, is therefore one of our classic fields of activity.

• Automated tests

Automated tests use special software tools to execute and check test cases independently.
This type of testing is particularly effective when carrying out recurring test cases or when checking large amounts of data.
Automated tests enable high efficiency and consistency as they can be performed faster than manual tests and are less prone to human error.
Common applications include regression tests, load tests and performance tests.
Of course, automated tests also require a certain amount of (wo)manpower in terms of implementation and evaluation over the last mile, which we also cover with our outsourcing offer.

Expert tip: The open source tool Selenium is particularly popular for automated testing of web-based software.
See our other blog article.

• Other test types

In addition to the basic forms of testing mentioned above, there are a number of other specific terms for certain types of testing, which we will only mention here as an overview:

• Functional testing: Checking the functionality of the software against the functional requirements to ensure that the software does what it is supposed to do.
  A subtype is “smoke testing“, often referred to as “build verification testing”: This involves carrying out a rudimentary test of the functionality of an application to ensure that the most important functions work without errors. The aim is to quickly identify the stable parts of the software before they are subjected to a more in-depth and detailed test of the functionality as a whole (known as a “system test“).
• Non-functional tests: Evaluate the performance, usability, reliability and security of the software.
• Integration tests: Focus on finding errors in the interfaces and interactions between several software modules or systems.
• Acceptance testing: Performed to confirm that the software is ready for delivery and fully meets the needs of the end user.

How do you carry out software testing correctly?

In practice, it is crucial that software testing is carried out systematically, professionally and completely in order to ultimately deliver flawless and functional software.
Process-related or structural errors are particularly treacherous here and can hinder the success of entire projects.

1. Planning and preparation

Successful software testing begins with solid test planning.
This includes the definition of test objectives, the selection of test methods and the allocation of resources.
Above all, it is important to set clear and measurable goals in order to be able to evaluate the success of the test process.

2. Test case development

The next step is to develop test cases that cover all aspects of the application.
This includes functional, non-functional, performance and security aspects.
Good test cases are specific, measurable, realizable, relevant and time-bound.

3. Test execution and documentation

The previously clearly defined test cases must be carried out in accordance with a structured test plan.
All errors and discrepancies must be documented in accordance with defined standards and categories in order to facilitate their tracking and rectification.

4. Results analysis and reporting

The test results are then analyzed on the basis of the documentation in order to understand the causes of errors and derive measures to improve software quality.
It also makes sense to create reports containing the test results and recommendations for the project team.

Our tip: The results of the testing can often even provide learnings not only for the specific project, but also for future projects with the same team or the same client!
It can therefore be useful to share test reports or a brief summary of them with the entire team.

Typical sources of error in software testing

In the following, we would like to point out some sources of error that we have found to occur frequently:

• Incomplete test coverage: Not all parts of the application are tested, which can lead to undetected errors.
  This is mainly due to the fact that steps
  1. and
  2 (see above) are not carried out carefully.
• Lack of realistic test data: Tests performed with unrealistic data cannot accurately predict the behavior of the software in the real world.
  As part of planning and preparation (step 1), it should be ensured that this problem is avoided and reliable data sources are used.
• Over-reliance on manual testing: Exclusively performing manual tests is time-consuming and error-prone.
  That’s why we also rely on a balanced mix of manual and automated tests to increase efficiency and reliability.
• Neglect of non-functional requirements: Security, performance and, above all, usability are just as important in testing as functional requirements and should be tested accordingly.

And finally: Which constellations harbor particularly high risks for errors in software testing?

• Agile development environments: In agile environments, where flexibility and fast iterations are required, it is important to implement fast feedback through so-called continuous integration and continuous testing.
  Here is a brief explanation:
  • Continuous Integration (CI): Continuous Integration (CI) is a software development practice in which team members frequently integrate their work – often several times a day – into a shared repository (central storage location).
    Each integration is then automatically verified by building the software and running automated tests.
    This enables teams to identify and fix problems early on, resulting in higher software quality.
    CI aims to speed up and simplify the integration process by reducing the time and effort required to integrate changes.
  • Continuous Testing (CT): Continuous Testing (CT) is the process of executing automated tests as part of the software delivery pipeline to obtain feedback on business risk as quickly as possible through a software release.
    CT takes place at all stages of the development cycle, from initial coding to delivery and beyond.
    The aim is to identify and correct software errors as early and as often as possible.
    Continuous testing helps to continuously check the quality of the software and ensure that it meets user requirements before it goes into production.

• Large projects with multiple teams: In large projects, a coordinated test strategy is crucial to avoid overlaps and gaps in test coverage.
  The use of common test standards and tools can improve consistency and efficiency.
  It also makes sense to set up joint coordination of testing.
• Projects with high security requirements: In projects where security is a high priority, such as in the financial or healthcare sector or for software for so-called critical infrastructures, specialized security tests and regular penetration tests are essential, even after the software has been implemented.

Conclusion

Software testing is a complex but essential process that contributes significantly to the quality assurance of software products.
By following the best practices mentioned above and adapting the testing process to the specific requirements and constellations of a project, IT outsourcing providers can ensure that their software products meet the highest quality standards.