What is Black Box Testing? Types and Techniques

Black Box Testing is software Testing Method in which the internal design; internal implementation of the item is not visible to tester. In this method of testing examines functionality of the application without peering into the internal structure of application. No need to have prior programming knowledge.

Black Box Testing
Black Box Testing

This type of testing is based on the basis of Software Requirements and specifications. In this type of testing Tester focuses on input and output of the software system and doesn’t bother to know about the internal working of the software. This type of testing does not require programming knowledge so this one is easy to perform.

How to do Black Box Testing?

  • Requirements and specifications are examined.
  • Tester chooses some valid inputs and some invalid outputs to check.
  • Prepare test cases which can cover maximum inputs.
  • Execute the test cases.
  • Compare actual outputs with the expected output.
  • We fix the defects if found.
  • Retest the founded defects.

Types of Black Box Testing:

There are three types of black box testing. I will explain you about all these types. we will discuss about all these in separate topics too.

Functional Testing

  • It is performed to check the functionality of the application and is performed by testers.
  • Functional Testing is not concerned with the source code of the application.
  • So, Mostly used tools are Selenium, Qtp, Junit .
  • Software functionality can be tested without knowing the internal working of that software.
  • On the positive side it is better that we don’t need to know about coding skills but on the negative side due to this we can miss some test cases because we are not having any knowledge about programming skills.
  • There are many types of functional testing. We are listing some types of functional testing:
    • Unit Testing
    • Smoke Testing
    • Component Testing
    • Integration Testing
    • Regression Testing
    • Sanity Testing
    • System Testing
    • User Acceptance Testing

Non – Functional Testing

  • It is a type of software testing in which we test non-functional aspects of a software application.
  • Another key point of non functional testing that it is also equally important as functional testing.
  • In this type of testing we check about the performance, usability etc. of software application.
  • Therefore, we always prefer this testing because we can rectify site load issue , performance issue etc.
  • Most widely used tools are Jmeter, neoload, load tracer etc.
  • We can understand non-functional testing by taking an example of social platform like Facebook.
  • For Example, We are creating an application where a large number of users will login at the same time, so we will check the performance of website when multiple users will try to login at same time.
  • Here we are listing some types of non-functional testing:
    • Baseline Testing
    • Documentation Testing
    • Load Testing
    • Performance Testing
    • Security Testing
    • Volume Testing
    • Usability Testing
    • Endurance testing
    • Scalability Testing
    • Compliance Testing
    • Stress Testing
    • Efficiency Testing
    • Recovery Testing

Regression Testing

  • We verify that change in code of the software application doesn’t impact the functionality.
  • we make sure that new changes in the code should not have any effect on existing functionalities of that software application
  • Tools are used to perform regression testing are QTp, selenium etc.

Black Box Testing Techniques

There are various black box testing techniques. Some of the techniques are as follows:

  • Decision Table Testing
  • Equivalence Class Testing
  • Boundary Value Testing
  • Error Guessing
  • State Transition Testing
  • Syntax Testing
  • Cause – effect  graph
  • Use case testing
  • Domain Analysis

Advantages of Black Box Testing

  • There is no need to have knowledge about programming languages.
  • we perform tests from the user’s point of view.
  • Efficient on large systems.
  • Testing process is simplified because tester only focuses on input and output. There is no connection with the internal structure of software application.

Disadvantages of Black Box Testing

  • In this type of testing, we cannot test all properties of software application.
  • Test cases are difficult to design.
  • There are chances of having unidentified paths.
  • Difficult to identify all possible inputs.

In this topic we have discussed about black box testing. If you want to know about white box testing , you can click on this link(White Box Testing).

Later on we will discuss about black box techniques in detail.It is very important to realize that if we want to have good software product, both these techniques are to be used.

Interview Questions

  • What are advantages of white box testing?
  • Explain stress testing?
  • What is recovery testing?
  • What do you mean by path coverage?
  • Why unit testing is important?
  • Who performs component testing?
  • Differences between black box and white box testing?

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