Application Testing – Into the Basics of Software Testing!

Introduction to Application Testing

Application Testing is an activity that is performed frequently by almost every software tester in his career. These two words are extremely broad in practical aspects.

However, only the core and most important areas will be discussed here. The purpose of this tutorial is to touch all the primary areas so that the readers will get all the basic briefings at a single place.

Application Testing

In a nutshell, Application testing is a process through which the functionality, usability, and consistency of the entire application is tested.

Application Testing: Explaining the Basics of Software Testing

Categories of Applications

Whether it is a small calculator software with only the basic arithmetic operations or an online enterprise solution; there are three categories of applications:

Categories of Applications

For desktop applications, testing should consider UI, business logic, databases, reports, roles and rights, integrity, usability, functionality, performance, security, hardware & software compatibility and data flow.

For web applications, testers should give sufficient importance to the performance, load, and security of the application.

The other main testing types covered under web application testing are functional testing, cross-browser testing, UAT, Beta testing, regression testing, compatibility testing, smoke testing, exploratory testing, compatibility & Multilanguage support testing and stress testing.

For mobile applications, the main types of testing that should be done are UI testing, Rule-based testing, regression, functional and security testing.

So AUT (application under test) is either a desktop software or a website or a mobile app.

Application Testing

Application Testing Methodologies

It is a well-known and well-discussed aspect that there are only 3 universally accepted testing methodologies:

#1) Black Box: In black-box testing, the AUT is validated against its requirements considering the inputs and expected outputs, regardless of how the inputs are transformed into outputs. Testers are least concerned with the internal structure or code that implements the business logic of the application.

Black Box

There are four primary techniques to design test cases for Black box Testing:

  • BVA (Boundary Value Analysis)
  • EP (Equivalence Partitioning)
  • Decision Tables
  • State Transition Tables (and diagrams)

Black box testing is commonly employed for functional, non-functional and regression testing.

#2) White Box: The primary focus of this methodology is to validate how the business logic of the application is implemented by the code/program.

White Box

The internal structure of the application is tested here and the techniques available to do so are:

Both of the above-listed techniques contain several other strategies that may be discussed in some other article. Some techniques are discussed in the ‘Test Case Design Techniques’ topic.

#3) Grey Box: Practically speaking, this is a mixture of the black box and white box.

Grey Box

In this methodology, the tester mainly tests the application with the Black-box approach. However, for some business-critical or vulnerable modules of an application, testing is done through a white box.

Application Testing Tools

There are a lot of Application testing tools available in the market today. This includes both paid and open-source tools. Moreover, some tools are purpose-specific.

For example, UI testing, Functional Testing, DB Testing, Load Testing, Performance, Security Testing, and Link validation testing. However, some tools are strong enough to provide the facility for testing several major aspects of an application.

The most important concept in ‘Application Testing’ is functional testing. Our focus will be on functional testing tools.

Here is the list of some of the most important and fundamental features that are provided by almost all of the ‘Functional Testing’ tools.

  • Record and Play
  • Parametrize the Values
  • Script Editor
  • Run (test or script with debug and update modes)
  • Report on Run session

Different vendors provide specific features that make their product unique when compared to the other competitor products. But the five features listed above are the most common ones and can be found in almost all the functional testing tools.

Given below is a list of few widely used Functional Testing tools.

1) HP QTP (Quick Test Professional)
2) Selenium
3) IBM Rational Robot
4) Test Complete
5) Push to Test
6) Telerik

Software Test Plan (STP)

Planning is always required for any activity and the same is applicable for software testing as well. Without a proper plan, there is always a high risk of getting distracted during the testing. If this risk becomes a fact, then the results could be horrible.

5 Main Parts of a Good Test Plan

#1) Scope

  • Overview of AUT
  • Features (or areas) to be tested.
  • Exclusions (features or areas not to be tested) with reason.
  • Dependencies (of testing activities on each other, if any).

#2) Objectives: This section describes the goals of testing activity e.g. validation of bug fixes, new features added or revamp of AUT, etc.

#3) Focus: This section describes what aspect of the application will be included in the testing e.g. security, functionality, usability, reliability, performance or efficiency, etc.

#4) Approach: This section describes what testing methodology will be adopted for which areas of AUT. For example, in the STP of an ERP application; the approach section may contain the information that black box testing will be the approach for payroll. However, for reports, the approach will be grey box testing.

#5) Schedule: This section describes who will be doing what, where, when and how on the AUT. The schedule section is a ‘4Ws and 1H’ of the STP. Normally, the schedule is prepared as a simple table, but every organization may have its own customized format according to their needs.

Once the test plan is ready and the application is under development, the testers will design and document the test cases. In the “Application Testing – Methodologies” section above, the TC design techniques are listed.

Application Testing Cycles

Once the AUT is ready for testing, the practical phase of the testing cycle starts in which testers execute the test cases on AUT. Keep in mind that here the testing cycle is discussed regardless of Testing Levels (Unit, Module, Integration, System and User Acceptance) and Testing Environments (Dev, QA, Client’s Replica, Live).

#1) Smoke Testing: This is the very first testing cycle. The purpose of smoke testing is to verify that there are no crashes in the application and it is suitable for further testing. This step is wide and shallow.

#2) Sanity Testing: This is the second testing cycle. It’s purpose is to verify that a specific module is working properly and is suitable for complete testing. This step is narrow and deep.

Pro Tip: Usually, ample amount of time will not be available to run the above two cycles separately. So, a mixture of both these cycles is adopted in practice.

#3) Functional Testing: A proper and full-fledged testing of the application is performed in this application test cycle. The primary focus of this activity is to verify that the business logic of the application is working as expected.

#4) Regression Testing: This is the final application cycle. Here, the bug-fixes and/or updates are verified. Moreover, regression testing also ensures that there is no malfunctioning in the other areas of AUT due to fixes and changes.

Bugs are logged in every testing cycle. There is no distinct borderline between the testing cycles. For example, in Regression, the Functionality is also verified and it may also require smoke, sanity or their merger first.

We have discussed the above in four different application testing cycles. We also need to understand here that each application test cycle has certain steps involved in it. Generally, any testing cycle has the steps as presented in the image below.

Application Testing Cycles

Application Testing – Best Practices

There are hundreds of articles available on the internet about this. Every article suggests a different number of best practices ranging from 7 to 30 (that I have seen so far). However, we only have 5 tips for our readers.

  • Plan Properly
  • Test Keenly
  • Log the bug Clearly
  • Do the Regression Test Efficiently
  • Improve the above four skills Continuously

Furthermore, you should prioritize the test cases well and cover the main business flows first.


Application Testing is a vast subject and it is the primary activity for almost all the software testers.

In this tutorial, we have provided an overview of the most fundamental and necessary areas that fall under application testing.

It involves strategies, phenomena, approaches, tools, technologies, and guidelines. We have addressed the conceptual and practical insight of application testing along with its most prominent areas of concern.

Feel free to share your thoughts on this article in the comments section below.

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62 thoughts on “Application Testing – Into the Basics of Software Testing!”

  1. I have 15+ years in the QA TESTer field in Silicon Valley, CA, and should tell you all, that the written articles here describe all meanings of testing so clear and precise! These articles can be used to create a Test Plan for any kind with the editing, of course, to make it shorter!


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