Top 70 Functional Testing Interview Questions And Answers

This list covers all the important Functional Testing interview questions for freshers and professional-level candidates. This Software testing interview questions guide will help you crack any interview and help you get your dream job in the field of software testing.

1) What is Functional Testing?

Functional Testing is a software testing method that helps you to validate the software system against the functional requirements/specifications.

2) What is the purpose of Functional Testing?

The main purpose of Functional tests is to test each function of the software application by offering appropriate input and verifying the output against the Functional requirements.

3) What kind of testing covers functional Testing?

Functional Testing involves black box testing and is not concerned about the application’s source code. This Testing checks the User Interface, APIs, Database, Client/Server communication, and various other Application functionalities Under Test. This software testing method can be performed either manually or using automation.

4) What do you test in Functional Testing?

Here are some reasons for using Functional Testing:

  • Mainline functions: It tests the main functions of an application
  • Basic Usability: This method involves basic usability testing of the system. It also checks if the user can freely navigate the screens without difficulties.
  • Accessibility: It checks the accessibility of the software system for the user
  • Error Conditions: You can use the testing techniques to check for error conditions. It also checks if relevant error messages are displayed.

5) What are the important steps that are covered in Functional Testing?

Functional Testing is done by following steps:

Step 1) Requirements specified by the user or organization are studied, then clear all the doubts and queries.

Step 2) Based on the specified requirements, test cases are designed by keeping in mind all the test scenarios that must be covered for all test cases.

Step 3) Identify all test data required to check the system’s functionality and determine the input.

Step 4) Determine the expected output based on the input values and functionality.

Step 5) After this tester execute all test cases to check whether they are performing well or not

Step 6) Compare the outcome with the expected output and determine the system’s defect rate and accuracy.

6) What is the use of a Traceability Matrix?

Traceability matrix shows the relationship between test cases and requirements with the help of one document.

7) What is the difference between functional and non-functional testing?

Functional Non-functional testing
Functional testing is performed before non-functional testing. Non-functional testing is always performed after the functional testing.
It is based on customers’ requirements. It is mainly focuses on customers’ expectations.
It helps to validate the behavior of the application. It helps to validate the performance of the application.
It describes what the product does. It describes how the product works.

8) What are the different Test Levels?

There are four test levels:

  • Integration testing: Integration Testing is defined as a software testing method where software modules are integrated logically and tested as one group.
  • System testing: System Testing is a level of testing which validates the complete and fully integrated software product.
  • Acceptance testing: Acceptance Testing (UAT) is a type of testing performed by the end-user or the client to verify/accept the software system before moving the software application to the production environment.
  • Unit/component/program/module testing: It uses for testing all the components and modules under test

9) What is the use of Acceptance Testing?

Acceptance testing determines whether the software system has met the required specifications. The main aim of this type of test is to evaluate the system’s compliance with the business needs and verify if it has met the needed criteria for delivery to end-users.

10) What Is Adhoc Testing?

Adhoc testing, also known as random testing, is a method of testing that does not follow any test cases or requirements associated with the application. In most cases, It is an unplanned activity where any part of the application is randomly checked to find defects.

11) What Is Mean by Equivalence Partitioning?

Equivalence partitioning is also called equivalence class. It is a black box testing that divides input data into data classes. This software testing process helps you to decrease the number of test cases while still covering the maximum requirement.

12) What is Boundary Value Analysis?

It is a technique for analyzing the boundary values of Equivalence class partitions. This testing technique helps you identify errors at the boundaries rather than within the range values.

13) When to Do Smoke Testing?

Smoke is a testing method performed on the system after receiving the build. This type of testing method checks for the critical path and not the functionality to ensure that the build is accepted for further testing or it should be rejected in case of a broken system. Smoke Testing also checks the system’s critical path, without which the application is blocked.

14) Why do we need to conduct end-to-end Testing?

End-to-end testing is a method that allows you to execute tests that cover all the possible flow of the testing application from start to finish basis. This software testing approach helps you to discover software dependencies and assert that the correct input is passed between different software modules and sub-systems.

15) What do you understand by Sanity testing?

Sanity testing is conducted after receiving the build to check the new functionality/defects that need to be fixed. In this type of testing, the goal is to check the functionality, determine whether the bug is fixed, and test the effect of the fixed bug on the application under Test.

16) What is the difference between severity and Priority?

Defect Severity is a level or the degree of impact by the defect on the application under Test. You should remember that the higher the severity of the defect, the more it will impact the application.

17) What is RTM?

Requirement Traceability Matrix is a full form of RTM. It is a tool that helps the tester helps you to keep track of requirement coverage over the testing process. Once the requirement document is received. It is created based on the requirements and maintained until the specific system or application is released.

18) What is Data-driven Testing?

Data-driven Testing is a famous functional testing method where test scripts are executed repeatedly with the help of data sources like spreadsheets, Excel, CSV files, XML files, and SQL database files. You can use these data sources are used as input values to generate the output. After that, its’ outcome is compared expected to verify the system or software.

19) What is Mutation Testing?

The purpose of mutation testing is to verify whether a set of test data or test cases is useful or not. It is done by deliberately adding various code changes (bugs) and re-testing with original test cases or data.

20) Why is it impossible to test a program thoroughly?

Here are the two important reasons it makes it impossible to test a program entirely.

  • Software specifications can be subjective and may lead to different interpretations.
  • Sometime program may demand lots of inputs, outputs, and path combinations.

21) How can you test a product if the requirement is yet to freeze?

If the required specifications are unavailable for a specific product, then the test plan can be prepared based on the assumptions made about the product.

22) What are important points you need to remember while considering while writing Test Cases?

Here are few vital points that you should be considered while writing Test Cases:

  • Before beginning to write the test cases, you must clearly understand the client’s needs.
  • You should include every requirement in the form of test cases, and nothing should be left out.
  • All functional and non-functional requirements should include a UI interface, and compatibility must be covered.
  • Test cases should be evaluated continuously to avoid any repetition or redundancy.
  • Priority is also very important factor that should be set for test cases while writing.
  • Test cases can also be built Sprint so that the tester and the developer help you analyze the product’s quality based on test case execution.
  • The structure of test cases must be easily understood and must be written in simple language.

23) How many test cases can you execute in a day?

Be practical while answering this kind of real time manual testing interview questions. It also depends on the test case complexity and size. Some test cases have few test steps, and some have more.

A sample answer should be, “In my earlier project, we generally execute 35-40 simple test cases per day, 15-17 medium test cases (like Assigning user roles) per day, and 5-7 complex test cases per day.

24) What is Stress Testing?

Stress Testing is a performance testing method in which the application is bound to go through exertion or stress. For example, execution of an application above the break threshold to determine the point where the software program crashes.

25) What is Load Testing?

Load Testing is a performance testing method where the application is executed beyond various load levels. It helps you monitor the server’s peak performance, response time, etc. Using this performance testing method, you can determine the application’s stability, performance, and integrity under parallel system load.

26) What is Configuration management?

It is a system engineering method for establishing and maintaining consistency of a product’s physical, performance, functional, design, and operational information. It brings cost efficiency and better time management to your organization.

27) What are the important factors to be considered in Risk-based Testing?

  • It enables you to identify when and how to implement risk-based Testing on an appropriate application.
  • You can identify the measures that act well while searching and handling risk in critical areas of the application.

28) What is Non-functional Testing?

Non-functional testing is a software testing approach to checking non-functional aspects like performance, usability, and reliability of a software application. It is mainly designed to test the readiness of a system according to nonfunctional parameters, which are never addressed by functional Testing.

29) What are the main advantages of Automation testing?

Here are the advantages of Automation testing:

  • It provides support for the execution of repeated test cases
  • It helps in testing a large test matrix
  • It allows parallel execution and also encourages unattended execution

Click here to learn more about Automation testing.

30) What is covered, and what are the different coverage techniques?

There are three basic types of coverage techniques, and they are:

  • Statement coverage: This coverage method ensures that each line of source code has been executed and tested.
  • Decision coverage assures that every decision (true/false) in the source code has been executed and tested.
  • Path coverage: Ensure that every possible route through a given part of the code is executed and tested.

31) What is a Bug report?

A software tester records their observations, fact-findings, and other helpful information to the developers during the software testing. All this data related to the test record is also called a bug report.

A detailed bug report is essential for production during Testing.

  • It helps you to understand the problem
  • The environment and the specific conditions under which it happens
  • The resolution if/when the software developers fix the problem

32) What is GUI testing?

GUI testing is Graphical User Interface testing which tests the interface between the software and the end-user.

33) What are the standard rules of an API test design?

Here are the key principles of an API test design:

  1. Setup: Create objects, start services, and initialize data.
  2. Execution: Apply API or the scenario, including logging
  3. Verification: Allows evaluation of the result of the execution
  4. Reporting: Display statuses like Pass, failed, or blocked status
  5. Clean up: Pre-test state

34) What are the advantages of Manual Testing?

Here are the advantages of using the manual testing method:

  • It is a method when compared to automated Testing
  • Analysis of the product from the point of view of the end-user is possible only with manual Testing
  • You can do GUI testing more accurately with the help of manual Testing, as visual accessibility and preferences are difficult to automate
  • Manual testing is easy to learn for new people who have just entered into Testing
  • It is suitable for short-term projects when test scripts are not going to be repeated and reused
  • It is best suited when the project is at the early development stages

35) What is the Test Harness?

A Test Harness gathers software and test information to test a program or unit by running it under changing conditions like stress, data-driven, and monitoring its behavior and outputs.

36) What is Test Closure?

Test Closure is a document which summarizes all the tests conducted during the SDLC (Software development life cycle) and offers a detailed analysis of the bugs that are removed and errors found.

This document also contains the aggregate no. of experiments, total numbers of experiments executed, total numbers of imperfections discovered, add numbers of bugs not settled, the total number of bugs rejected, etc.

37) What is a critical bug in Functional Testing?

A critical bug is a bug that can affect the majority of the functionality of a specific application. It also means a large piece of functionality or major system is completely broken, and there is no workaround to move further.

38) What is Baseline Testing?

A baseline test is a series of tests that are run to collect performance information. The information gathered can also be used to enhance the performance and capabilities of the application by making changes according to the results. This testing method compares the present performance of the application with its previous performance.

39) What is Defect Cascading?

It is a technique for triggering other defects in the application when any defect remains noticed while testing. It invokes other application defects because multiple defects crop up in the later stages of development.

However, If defect cascading affects other features in the application, identifying the affected feature becomes quite challenging. You may make various test cases to solve this issue.

40) Name all the basic components of the defect report format.

The basic components of the defect report format include:

  • Project Name
  • Module Name
  • Defect detected on
  • Defect ID
  • Defect Name
  • Screenshot of the defect
  • Severity and Priority status
  • Defect resolved by and resolved on

41) What is a Testbed?

Testbed is software, hardware, and other test items used to support the testing process. The primary purpose of the testbed is to control and monitor the conditions of the tests.

It also offers means to perform tests. In manual software testing, the testbed comprises several tools and technologies.

Examples include programming languages like PHP, Perl frameworks like Joomla or WordPress, and databases like PostgreSQL or MySQL.

42) What is Defect Removal Efficiency?

The Defect Removal Efficiency (DRE) is a testing metric that indicates how effectively the development team can fix errors and issues prior to the release of the product. It measures defects’ ratio to the number of discovered issues. For example, if there were 80 discovered during the Testing and 60 were fixed, the DRE will be 80/60 = 1.3%.

43) What is the difference between Bug release and Bug leakage?

Bug release is when a specific software version is released with known bugs. These bugs are primarily of low Priority or severity, while Bug leakage happens when a bug is identified by the end customer who is not recognized by the software testing.

44) What is agile testing, and why it is import?

Agile Testing helps you to evaluate software from the perspective of the customer. It does not need the development team to complete coding before starting the Quality Audit process. Instead, the Testing and coding process goes simultaneously. However, it may need continuous customer interaction.

45) What will you do as a tester when encountering a bug?

After finding the bug, we need to lock the bug in the bug report. Then this bug should be assigned and communicated to developers who can fix it. After the developer fixes the bug, all the bugs must be re-tested, and determinations must be made regarding the need for regression testing to ensure that fixes didn’t create problems anywhere else.

46) What are the different types of Debugging Categories?

Various categories for debugging are:

  • Brute force debugging
  • Cause elimination
  • Slicing of Program
  • Backtracking
  • Fault tree analysis

47) What is the Test Deliverable?

Test deliverables are a group of tools, documents, and components that are maintained and developed to support the Test.

Here are the test deliverables at various testing phases of the software development lifecycle:

  • Before Software Testing
  • During Software Testing
  • After the Software Testing

48) What are the common risks that lead to project failure?

Here are the common risks that lead to project failure:

  • Not having sufficient human resource
  • There is a huge risk that the testing environment may not be set up properly
  • Limited Budget

49) What are the significant differences between Test Matrix and Traceability Matrix?

Here are the significant differences between Test Matrix and Traceability Matrix:

  • Test Matrix: The test matrix helps you to capture actual quality, effort, the plan, resources, and time needed to capture all phases of software testing
  • Traceability Matrix: This Matrix involves mapping between test cases and customer requirements.

50) What are Positive and Negative Testing?

We can say that positive Testing is conducted tester puts in a valid input and expects some action to be completed according to the specification, while a negative test is done when you put in any invalid input and receive errors.

51) What is Big Bang Approach?

The Big Bang is a widely used integration testing strategy that requires side-by-side checking all system components. The main benefit of this testing method is that the tester can check the work of the entire system and its components.

52) What is the meaning of a Fault?

A fault is a condition that leads to the failure of software execution when performing a regarded function.

53) What is Bug leakage in functional Testing?

Bug leakage occurs when a bug is identified by the end customer and missed by the testing team while testing the software.

54) What is TDD?

Test-Driven Development is a software development methodology. In this method, the development of the software is driven by test cases created for the functionality to be implemented. The test cases are created in the TDD method, and code to pass the tests is written.

55) What is the difference between Latent and Masked Defects?

A latent defect is an unidentified when defect present in the current release. However, it is not visible as the conditions in which the defect could be found have never been met. These defects occur only when software testing triggers a particular event, concealing their presence.

56) What is Random/Monkey Testing?

Random testing method is also known as monkey testing. In such a type of testing, data is generated randomly, often using a tool or automated mechanism. Your system is tested with this randomly generated input, and the results are analyzed.

57) What is Context-driven Testing?

Context-driven testing involves adopting the test practices, approaches, and methodologies and, at times, customizing them based on the context of the project.

58) What is the PDCA cycle in software testing?

PDCA cycle is an essential key for continuous process improvement in software development.

It consists of the following 4 steps:

  • Plan: Plan the objectives, goals, and initiatives that help reach customer satisfaction.
  • Do: It implements the plan into action. It helps serve the customer with better quality and satisfaction; it is essential to have a good plan to execute.
  • Check: To check your plan’s progress, which has been implemented. The result also shows how accurate the planning had been.
  • Act: Acting upon the results to further improve helps the tester achieve the planned goals.

59) What are the entry criteria in Software Testing?

A set of prerequisites are required to kick off the testing activity, including the Test environment, Test tool, Test Data, and many more.

60) What is exit criteria in Software Testing?

An exit criterion is a set of conditions that specify the agreed-upon features or state of the application to mark the completion of the process or product.

61) Can system testing be done at any stage?

All the software components are tested to ensure that the product fulfills the specified requirements. Therefore, system software testing can’t be done at any stage. Instead, system testing must start only when all modules or units work correctly and are in place.

62) What is meant by Alpha, Beta, and Gamma Testing?

All of the givens are the name of software testing terms:

Alpha testing is conducted by the developers who develop the software and testers. Sometimes it is observed that the alpha testing is conducted by the purchaser or outsourcing team without developers or testers.

A specified number of ultimate users conducts beta testing before delivery. Mostly, it is conducted at the place of the end-user.

Gamma testing: This testing approach checks the specified needs when the software is all set for release. It is generally done at the place of the ultimate user. It is also performed firsthand by omitting all the in-house testing activities.

63) What can be understood from End-To-End Testing?

End To End testing system is a method of testing an application to ensure whether or not it is acting as expected to be working. It is used to test the application flow from the start to the endpoint. The end-to-end testing system helps you scrutinize the system’s complete flow. This testing method also confirms that the data integrity is maintained between the different system components and the systems.

64) What is Use Case Testing?

Use-case testing is a method that allows us to test the functionality of a specific piece of software. It also helps you to understand why we should or shouldn’t be using software in the first place.

65) What is A/B Testing?

A/B Testing tests two or more different versions of your software with users to assess which version performs better. It is a low-risk method of testing new or existing functionality variations.

You can select a part of your users to use feature A. The other group uses feature B. After this, you can check the user feedback and response using statistical Testing to determine the final version of the feature.

66) What is the Defect Life Cycle?

The defect life cycle, which is also known as the bug life cycle, is a series of phases during which a defect goes throughout its life cycle. This software testing life cycle begins as soon as the tester finds or reports the defect and ends when the QA tester ensures that the defect is resolved so that it does not occur again.

67) What is Configuration Testing?

Configuration testing is a software testing method that is used to evaluate the configurational requirements of the software. It helps you discover the optimal configuration of the system under which the application performs. It also helps you to identify and resolve any compatibility issues.

68) What Determines the level of risk?

The possibility of an adverse event and the event’s effect decide the level of risk.

69) What do you mean by Defect Triage?

Defect triage is a method in which defects are prioritized depending on various characteristics like severity, risk, and the amount of time it will take to fix the problem. The defect triage meeting brings together stakeholders like the development team, testing team, project manager, etc.

70) What is a Stub?

When top-down integration testing is performed, lower-level modules are often not produced until top-level modules are tested and integrated. Stubs are dummy modules used in these circumstances to emulate module behavior by delivering a predicted or hard-coded result based on the input variables.