Visit here for our full ISTQB CTFL v4.0 exam dumps and practice test questions.
Question 141:
What is the purpose of stress testing?
a) To verify that the system functions correctly under normal load
b) To test the software’s behavior under extreme conditions
c) To evaluate the user experience and usability of the system
d) To check whether the system meets functional requirements
Answer:
b) To test the software’s behavior under extreme conditions
Explanation:
Stress testing is a type of performance testing that evaluates how a system behaves under extreme or unusual conditions. The goal of stress testing is to identify the system’s breaking point — the level of load or stress that the system can no longer handle effectively. Stress testing is used to determine how the system responds when it is pushed beyond its expected operational capacity, such as during unusually high traffic, unexpected spikes in usage, or large data volumes.
Stress testing helps identify weaknesses in the system, such as bottlenecks, resource exhaustion, memory leaks, or potential points of failure that could occur under extreme conditions. This allows developers to address these issues before the software is deployed to production, ensuring that the system is resilient under stress.
Option a is incorrect because normal load testing focuses on evaluating the system’s performance under regular, expected usage conditions, not extreme conditions. Option C is incorrect because usability testing is concerned with assessing user experience, not system behavior under stress. Option d is incorrect because functional testing verifies that the system meets functional requirements, not its behavior under stress.
In summary, stress testing is focused on testing the system’s behavior under extreme conditions to identify weaknesses and ensure robustness.
Question 142:
Which of the following is the primary purpose of configuration management in software testing?
a) To automate the execution of test cases
b) To track and control changes to the software and testing environment
c) To monitor system performance during testing
d) To ensure that the software meets user acceptance criteria
Answer:
b) To track and control changes to the software and testing environment
Explanation:
Configuration management is a crucial aspect of software development and testing that involves tracking, controlling, and managing changes to the software code, documentation, testing environments, and related assets. The goal of configuration management is to ensure that all components of the software and its environment are properly documented, controlled, and consistent throughout the development and testing process.
Configuration management helps in:
Version control: Keeping track of changes to the software’s codebase, ensuring that the right version of the code is used during testing.
Environment consistency: Ensuring that the testing environment is stable and consistent across different testing stages, avoiding issues caused by mismatched environments.
Traceability: Maintaining clear records of changes, allowing teams to trace defects back to specific changes in the code or environment.
Option a is incorrect because automation of test cases is a separate activity related to test automation, not configuration management. Option C is incorrect because performance monitoring is a focus of performance testing, not configuration management. Option d is incorrect because user acceptance criteria are primarily tested during acceptance testing, not configuration management.
In summary, the primary purpose of configuration management in software testing is to track and control changes to the software and testing environment, ensuring consistency and traceability throughout the testing process.
Question 143:
What is the main goal of regression testing?
a) To ensure that the new features meet the user’s expectations
b) To verify that recent code changes have not negatively impacted existing functionality
c) To validate that the software meets all functional requirements
d) To test the system’s performance under stress
Answer:
b) To verify that recent code changes have not negatively impacted existing functionality
Explanation:
Regression testing is a type of software testing conducted after code changes, such as bug fixes, feature enhancements, or updates, to ensure that the new changes have not introduced defects or caused unintended side effects in the system’s existing functionality. The primary goal of regression testing is to verify that previously working features continue to function correctly after new changes have been made.
Regression tests typically cover the areas of the software that have been impacted by the changes, but they can also include previously tested areas to ensure that no new defects are introduced in the overall system. The process helps to prevent regressions — situations where new changes negatively affect the existing system.
Option a is incorrect because ensuring new features meet user expectations is the goal of functional testing, not regression testing. Option C is incorrect because verifying the functional requirements is part of functional testing, not regression testing. Option d is incorrect because stress testing is focused on evaluating performance under extreme conditions, not the impact of code changes.
In summary, the main goal of regression testing is to verify that recent code changes have not negatively impacted the existing functionality of the software.
Question 144:
Which of the following testing techniques focuses on the internal logic of the software?
a) Black-box testing
b) White-box testing
c) Grey-box testing
d) Acceptance testing
Answer:
b) White-box testing
Explanation:
White-box testing, also known as clear-box testing or structural testing, focuses on testing the internal logic and structure of the software. Testers have access to the source code and design documents, which allows them to test the internal workings of the system, such as control flow, data flow, and code paths.
White-box testing aims to ensure that all possible code paths are executed and that internal functions, loops, and conditional statements work as expected. It is particularly useful for identifying logical errors, missing code branches, and security vulnerabilities.
Option a is incorrect because black-box testing focuses on testing the software’s functionality without knowledge of its internal workings, i.e., testers do not have access to the code. Option C is incorrect because grey-box testing combines aspects of both white-box and black-box testing, where the tester has partial knowledge of the internal workings of the system. Option d is incorrect because acceptance testing focuses on validating whether the system meets user requirements and business needs, not the internal logic of the software.
In summary, white-box testing focuses on testing the internal logic and structure of the software, with access to the source code.
Question 145:
Which of the following is an example of a non-functional requirement?
a) The system should support 1000 concurrent users
b) The system should allow users to submit feedback
c) The system should allow users to upload files
d) The system should provide users with search functionality
Answer:
a) The system should support 1000 concurrent users
Explanation:
Non-functional requirements are requirements that specify the qualities or attributes of the system, such as performance, security, usability, and scalability, rather than specific behaviors or functionalities. These requirements describe how the system should perform rather than what it should do.
In this case, the requirement that the system should support 1000 concurrent users is a non-functional requirement because it describes a performance aspect of the system related to its scalability and capacity. Non-functional requirements ensure that the system can handle expected loads, remain responsive, and provide a good user experience.
Options b, c, and d are all functional requirements because they describe specific features or functionalities that the system should provide, such as submitting feedback, uploading files, and providing search functionality.
In summary, non-functional requirements describe qualities like performance, scalability, and security, while functional requirements describe specific features or behaviors of the system.
Question 146:
Which testing technique is best suited for testing the system’s behavior without knowledge of the internal code?
a) White-box testing
b) Black-box testing
c) Grey-box testing
d) Integration testing
Answer:
b) Black-box testing
Explanation:
Black-box testing is a testing technique where the tester does not have access to the internal workings or source code of the system. Instead, the focus is on testing the functionality of the system by providing inputs and examining the outputs. The tester is concerned only with whether the system behaves as expected based on the specified requirements, without knowing how the system processes the inputs internally.
Black-box testing is commonly used for functional testing, acceptance testing, and system testing, where the goal is to validate that the software meets its functional specifications and provides the correct outputs for given inputs.
Option a is incorrect because white-box testing focuses on the internal logic of the system, not on behavior based on inputs and outputs. OptioC c is incorrect because grey-box testing combines aspects of both black-box and white-box testing, where the tester has partial knowledge of the internal workings. Option d is incorrect because integration testing focuses on verifying the interaction between different components of the system, not the overall system’s behavior without knowledge of its internal code.
Question 147:
Which type of testing is performed to ensure that new changes in the software do not affect the existing functionality?
a) Alpha testing
b) Regression testing
c) Integration testing
d) Acceptance testing
Answer:
b) Regression testing
Explanation:
Regression testing is a type of software testing that ensures that recent code changes, such as bug fixes, feature enhancements, or refactoring, have not introduced new defects or caused issues in previously working functionality. The primary goal of regression testing is to catch any unintended side effects of changes, ensuring that the new modifications do not negatively impact other parts of the system.
Regression tests are typically automated and run frequently, especially when the codebase changes often. The test cases are designed to cover both the modified and impacted areas as well as critical parts of the application that may be indirectly affected by the changes.
Option a is incorrect because alpha testing is the first phase of user acceptance testing, and it focuses on finding issues within the software in a controlled environment. Option C is incorrect because integration testing focuses on testing interactions between different system components, not on ensuring no existing functionality is broken. Option d is incorrect because acceptance testing focuses on validating the system against user requirements, not specifically on verifying that no existing functionality is broken.
In summary, regression testing is focused on verifying that new changes do not affect existing functionality.
Question 148:
What is the main goal of smoke testing?
a) To test the system’s performance under stress
b) To ensure that the basic functionalities of the software work
c) To verify that the software meets user requirements
d) To assess the usability of the system
Answer:
b) To ensure that the basic functionalities of the software work
Explanation:
Smoke testing, also known as “build verification testing,” is a preliminary type of software testing used to check if the basic and critical functionalities of a software build are working properly. It is typically the first step after receiving a new build or release, and its purpose is to determine whether the software is stable enough for further detailed testing.
The term “smoke test” comes from hardware testing, where engineers would power up a device and see if it “smoked” — indicating a critical failure. Similarly, in software testing, smoke testing checks for critical failures that would prevent further testing, such as the inability to launch the application or a major crash on startup.
Option a is incorrect because stress testing is focused on testing the system’s behavior under extreme conditions, not on checking basic functionality. Option C is incorrect because verifying user requirements is part of acceptance testing, not smoke testing. Option d is incorrect because usability testing focuses on user experience, not on verifying basic functionality.
In summary, smoke testing ensures that the essential features of the software work before proceeding with more detailed testing.
Question 149:
Which of the following is a key characteristic of black-box testing?
a) The tester has access to the source code and design documentation
b) The tester is concerned with testing the internal structure of the system
c) The tester focuses on verifying the system’s functionality based on inputs and expected outputs
d) The tester writes test cases based on code paths and decision branches
Answer:
c) The tester focuses on verifying the system’s functionality based on inputs and expected outputs
Explanation:
Black-box testing is a testing technique where the tester focuses on testing the software’s functionality without knowledge of its internal code or logic. The primary concern in black-box testing is whether the system behaves as expected given certain inputs and expected outputs. Testers are not concerned with the internal structure or workings of the system, only with its externally visible behavior.
Black-box testing is used to validate the system against the specified functional requirements, making sure that all functions perform as expected under different conditions. It is often used in functional testing, system testing, and acceptance testing.
Option a is incorrect because in black-box testing, testers do not have access to the source code or design documentation. Option B is incorrect because internal testing of structure and code paths is part of white-box testing. Option d is incorrect because writing test cases based on code paths and decision branches is part of white-box testing, not black-box testing.
In summary, black-box testing focuses on verifying the system’s functionality based on inputs and expected outputs, without knowledge of the internal structure.
Question 150:
What is the purpose of user acceptance testing (UAT)?
a) To identify defects in the system
b) To ensure that the system meets business requirements and is ready for deployment
c) To evaluate the system’s performance under load
d) To test individual components of the system
Answer:
b) To ensure that the system meets business requirements and is ready for deployment
Explanation:
User Acceptance Testing (UAT) is the final phase of testing before a software product is released to the customer or end-users. The primary goal of UAT is to verify that the system meets the business requirements and is ready for deployment. UAT is typically performed by the end-users or stakeholders who will be using the system in a real-world environment.
During UAT, the system is tested to ensure that it functions according to the business needs and user expectations. UAT verifies that the software delivers the intended value to the business and that it satisfies the user’s requirements for functionality, usability, and performance. Any issues found during UAT are addressed before the software is released to production.
Option a is incorrect because identifying defects is part of the testing process, but the main focus of UAT is to ensure the system meets business requirements, not just to identify defects. Option C is incorrect because performance testing evaluates system behavior under load, not business requirements. Option d is incorrect because component testing is part of unit or integration testing, not UAT.
In summary, the purpose of user acceptance testing is to ensure that the system meets business requirements and is ready for deployment.
Question 151:
Which of the following is a key advantage of automated testing?
a) It can only be used for performance testing
b) It requires less initial setup compared to manual testing
c) It can be executed frequently and consistently, saving time in the long run
d) It is suitable only for testing small applications with limited features
Answer:
c) It can be executed frequently and consistently, saving time in the long run
Explanation:
One of the key advantages of automated testing is that once the test scripts are created, they can be executed frequently and consistently. Automated tests can run quickly and can be easily re-executed with minimal effort, making them ideal for continuous integration and continuous delivery (CI/CD) environments.
Automated testing is especially beneficial in projects with frequent code changes or where repetitive testing is needed. By automating the tests, the team can catch defects early and ensure that changes do not break existing functionality. Over time, automated testing can save significant time and effort compared to manual testing, especially for regression testing and repetitive tasks.
Option a is incorrect because automated testing can be used for various types of testing, including functional, regression, and unit testing, not just performance testing. Option B is incorrect because while automated testing saves time in the long run, it requires a significant initial setup to create the test scripts. Option d is incorrect because automated testing is suitable for both small and large applications, especially those with complex features.
In summary, a key advantage of automated testing is that it can be executed frequently and consistently, saving time in the long run, especially for repetitive testing tasks.
Question 152:
Which testing technique is most suitable for testing the system’s performance under varying load conditions?
a) Load testing
b) Unit testing
c) Regression testing
d) Usability testing
Answer:
a) Load testing
Explanation:
Load testing is a type of performance testing designed to evaluate the system’s behavior under varying levels of load, such as different numbers of concurrent users or transactions. The goal of load testing is to assess whether the system can handle expected and peak usage without performance degradation, such as slow response times or crashes.
In load testing, the system is subjected to a defined load based on expected usage patterns, and the system’s performance is monitored to ensure it operates within acceptable limits. Load testing helps identify potential bottlenecks and scalability issues before the system is deployed to production.
Option B is incorrect because unit testing is focused on testing individual components in isolation, not on system performance. Option C is incorrect because regression testing ensures that new changes do not introduce defects in existing functionality, not performance issues. Option d is incorrect because usability testing focuses on assessing the user experience, not performance under load.
Question 153:
Which of the following describes the purpose of exploratory testing?
a) It involves executing predefined test cases to verify software functionality
b) It focuses on testing the system’s performance under extreme load conditions
c) It is an unscripted testing approach where testers learn and test the software simultaneously
d) It aims to assess the software’s usability and user experience
Answer:
c) It is an unscripted testing approach where testers learn and test the software simultaneously
Explanation:
Exploratory testing is a dynamic and unscripted testing approach where testers explore the software to understand its functionality, learn its features, and simultaneously design and execute tests based on their observations and experience. This type of testing does not rely on predefined test cases but instead encourages testers to use their creativity, domain knowledge, and intuition to identify potential issues, edge cases, and weaknesses in the system.
The key characteristics of exploratory testing include:
Learning and testing simultaneously: Testers begin testing without a full understanding of the software, but explore its features and behavior as they go. They quickly adapt and adjust their testing strategies based on what they discover.
No predefined test cases: Unlike traditional testing, which involves following a fixed set of test cases, exploratory testing is more fluid. Testers design and execute tests in real time, which helps uncover defects that might not be discovered with scripted tests.
Creativity and flexibility: Testers are encouraged to think creatively and explore the system in unconventional ways, which often leads to the discovery of unexpected issues, such as integration problems, UI inconsistencies, or usability issues.
Exploratory testing is especially useful in Agile development environments, where requirements may change frequently, and testers need to adapt to these changes quickly. It is typically conducted in early stages of development when there are limited or evolving test cases and when there is a need for a fast feedback loop.
It complements other types of testing by helping identify defects early, even in areas where no formal tests exist yet. Exploratory testing can be combined with automated testing or other testing techniques to ensure thorough coverage of both known and unknown areas of the software.
Exploratory testing has several advantages:
Increased test coverage: Because testers can focus on areas that are often overlooked in predefined test cases, exploratory testing may cover more areas of the software, especially edge cases or unusual workflows.
Quick feedback: As it allows testers to interact with the software directly, exploratory testing can provide fast feedback, helping developers identify and fix defects early in the development cycle.
Uncovering hidden defects: Since the tester’s understanding evolves throughout the testing process, they are often able to identify hidden defects that may not be apparent when strictly following predefined test scripts.
However, exploratory testing also has limitations. The lack of formal test cases can make it difficult to measure test coverage or track the specific areas tested, which could lead to missing critical areas if not managed properly. Additionally, since exploratory testing is driven by the tester’s intuition, it is not as repeatable or consistent as automated or scripted testing.
In summary, exploratory testing is an unscripted and adaptive approach to testing where testers learn and test the software at the same time, helping identify defects that might be missed in more formal, structured testing processes. It is particularly useful in Agile environments and early software development stages.
Question 154:
What does the term “test coverage” refer to in software testing?
a) The number of test cases executed during a testing cycle
b) The percentage of the software’s functionality tested
c) The time taken to complete all test cases
d) The number of defects found during testing
Answer:
b) The percentage of the software’s functionality tested
Explanation:
Test coverage is a metric used in software testing to measure the extent to which the software has been tested. It refers to the percentage of the software’s functionality, code, or features that have been covered or exercised by test cases. The goal of achieving good test coverage is to ensure that all areas of the software, including critical paths, edge cases, and potential failure points, are thoroughly tested to identify any defects early.
Test coverage can be measured at different levels, such as:
Code coverage: This is a common form of test coverage that refers to the percentage of source code that is executed by test cases. Code coverage can be further divided into different categories, such as:
Statement coverage: Ensures that each line of code is executed at least once.
Branch coverage: Ensures that every possible branch (decision point) in the code is executed.
Path coverage: Verifies that all possible paths through the code are exercised by the tests.
Functionality coverage: This measures the extent to which the features and functions of the software are tested. Functional test coverage ensures that all functional requirements are met and that each feature of the software has been tested for correctness.
Requirements coverage: This focuses on verifying that all the requirements, as outlined in the specification documents, have been tested. This ensures that the system behaves as expected according to the user or business requirements.
Achieving high test coverage is essential for ensuring software quality. A higher percentage of test coverage typically correlates with a higher likelihood of finding defects early in the development cycle. Test coverage can also be used to guide testing efforts, ensuring that critical areas are prioritized.
However, test coverage has limitations and is not a perfect indicator of software quality. High test coverage does not necessarily mean that the software is free from defects. For instance, test cases may cover every line of code, but they might not test the system under realistic user conditions or may miss critical edge cases. Also, measuring test coverage based solely on code coverage can miss out on the functionality or business requirements that the software is intended to fulfill.
Therefore, test coverage is one of many metrics that should be used in conjunction with other testing techniques, such as exploratory testing, user acceptance testing, and performance testing, to ensure the overall quality of the software.
In summary, test coverage is a measure of the extent to which the software has been tested, and it is typically expressed as a percentage of the code, features, or requirements that have been verified by test cases. High test coverage can help ensure that the system is thoroughly tested, but it should not be relied upon as the sole indicator of software quality.
Question 155:
What is the primary goal of performance testing?
a) To validate that the software meets the user’s requirements
b) To ensure that the system performs well under expected and peak load conditions
c) To verify the system’s security and identify vulnerabilities
d) To assess the system’s usability and user experience
Answer:
b) To ensure that the system performs well under expected and peak load conditions
Explanation:
Performance testing is a type of testing focused on evaluating how well a software system performs under various conditions, such as normal and peak load scenarios. The primary goal of performance testing is to ensure that the system performs efficiently, remains responsive, and operates within acceptable limits, even when subjected to heavy or varying loads.
Performance testing typically includes several types of tests, such as:
Load testing: This involves testing the system’s behavior under a specific load, such as the expected number of concurrent users or transactions. The goal is to assess whether the system can handle the expected volume of activity without significant performance degradation, such as slow response times or crashes.
Stress testing: Stress testing goes beyond normal load conditions and tests the system’s behavior under extreme or excessive load conditions to identify its breaking point. The goal is to determine how the system behaves when it is pushed past its capacity and to uncover potential issues like system crashes, slowdowns, or failures under stress.
Scalability testing: This type of performance testing evaluates how well the system scales when subjected to increasing load or demand. It helps determine whether the system can handle growth in terms of users, transactions, or data volume.
Spike testing: This involves testing the system’s response to sudden and sharp increases in load. It helps assess how the system handles unexpected surges in traffic or demand, such as during flash sales or marketing campaigns.
Performance testing is crucial for ensuring that the software meets the performance requirements specified by the user or business. It helps identify performance bottlenecks, resource limitations, and other issues that could impact the user experience. Without proper performance testing, users may experience slow response times, system crashes, or other performance-related problems, which could negatively impact customer satisfaction and business operations.
Option a is incorrect because validating user requirements is part of functional or acceptance testing, not performance testing. OptioC c is incorrect because security testing focuses on identifying vulnerabilities and ensuring the system is protected from attacks, not on performance. Option d is incorrect because usability testing assesses the system’s user experience, not its performance.
In summary, the primary goal of performance testing is to ensure that the system performs well under both expected and peak load conditions, providing a smooth user experience even under varying levels of demand.
Question 156:
What is the key difference between functional and non-functional testing?
a) Functional testing verifies the system’s security, while non-functional testing verifies functionality
b) Functional testing focuses on system behavior and features, while non-functional testing focuses on system attributes like performance and scalability
c) Functional testing is focused on usability, while non-functional testing is concerned with the system’s security
d) Functional testing verifies the system’s code, while non-functional testing focuses on testing the user interface
Answer:
b) Functional testing focuses on system behavior and features, while non-functional testing focuses on system attributes like performance and scalability
Explanation:
Functional and non-functional testing are two distinct categories of software testing, each focusing on different aspects of the system’s behavior.
Functional testing focuses on verifying that the system functions as expected, according to the defined specifications and requirements. It involves testing the software’s features, functions, and behavior to ensure that they perform correctly under normal conditions. Functional testing typically includes:
Unit testing: Testing individual components or functions of the software.
Integration testing: Verifying that different components of the system work together correctly.
System testing: Ensuring that the complete system meets functional requirements.
User acceptance testing (UAT): Validating that the system meets the user’s needs and business requirements.
Non-functional testing, on the other hand, focuses on evaluating the system’s attributes or quality aspects, such as:
Performance testing: Assessing the system’s performance under various load conditions, such as load, stress, and scalability testing.
Security testing: Ensuring that the system is secure from external attacks and vulnerabilities.
Usability testing: Evaluating the user experience, including the ease of use and navigation.
Compatibility testing: Verifying that the software works across different platforms, browsers, and devices.
The key difference between functional and non-functional testing is that functional testing focuses on verifying the system’s functionality and behavior, while non-functional testing evaluates the system’s attributes, such as performance, scalability, security, and usability.
Option a is incorrect because functional testing does not focus on security; that is part of non-functional testing. Option C is incorrect because usability testing is a type of non-functional testing, not functional testing. Option d is incorrect because functional testing is not focused on the code, and non-functional testing is not limited to the user interface.
Question 157:
Which of the following is the primary purpose of integration testing?
a) To ensure that individual components function correctly
b) To check whether different system components interact correctly
c) To verify the system’s performance under load
d) To assess the system’s usability and user experience
Answer:
b) To check whether different system components interact correctly
Explanation:
Integration testing is a type of software testing that focuses on evaluating the interaction between different components or modules of the system. The primary goal of integration testing is to verify that individual components, which may have been tested in isolation during unit testing, work together seamlessly when combined to form the complete system.
In integration testing, the focus is on testing the interfaces between different components or systems, ensuring that data is passed correctly and that there are no issues when modules interact. For example, if one module outputs data that is used by another module, integration testing ensures that the data is correctly transferred, processed, and used as expected.
Integration testing typically comes after unit testing, which focuses on testing individual components in isolation. While unit testing verifies that each component functions correctly on its own, integration testing checks whether the system works as expected when these components are integrated.
Integration testing may include:
Top-down integration testing: Testing starts from the top-level modules and moves downward, integrating lower-level modules step by step.
Bottom-up integration testing: Testing starts from the lowest-level modules and moves upward, gradually integrating higher-level modules.
Big-bang integration testing: All components are integrated at once, and the system is tested as a whole.
Option a is incorrect because individual components are tested during unit testing, not integration testing. Option C is incorrect because performance testing evaluates how the system behaves under load conditions, not the interaction between system components. Option d is incorrect because usability testing focuses on user experience and interface, which is not the primary concern of integration testing.
In summary, the primary purpose of integration testing is to verify that different system components work together as expected, ensuring that the system functions correctly when integrated.
Question 158:
Which of the following best describes the concept of “defect density”?
a) The number of defects found per test case executed
b) The total number of defects found in the software
c) The number of defects found per unit of code or functionality
d) The severity of defects found in the software
Answer:
c) The number of defects found per unit of code or functionality
Explanation:
Defect density is a metric used in software testing to quantify the number of defects or issues found in a specific area of the software, typically per unit of code or functionality. It helps evaluate the quality of the software by determining how many defects exist relative to the size of the codebase or the complexity of a particular feature or component.
Defect density is usually calculated as:
Defect Density=Number of DefectsSize of the Software Unit\text{Defect Density} = \frac{\text{Number of Defects}}{\text{Size of the Software Unit}}Defect Density=Size of the Software UnitNumber of Defects
Where the unit can be measured in terms of lines of code (LOC), function points, or any other relevant metric of size.
Defect density is a useful indicator of the overall quality of a system or component. A higher defect density could indicate that the software is less stable or that a particular module or feature may require more attention during development or testing. It can also help prioritize testing efforts by highlighting areas of the codebase that may need more in-depth testing.
However, defect density should not be used in isolation as the sole indicator of software quality. The severity, impact, and criticality of defects are just as important as the number of defects found. Additionally, the complexity of the software or system can affect defect density. For example, complex systems may have a higher defect density due to the difficulty in writing flawless code.
Option a is incorrect because defect density is not calculated per test case executed, but rather per unit of code or functionality. Option B is incorrect because defect density does not simply measure the total number of defects; it considers the size of the software or the functionality being tested. Option d is incorrect because defect density is not about the severity of defects, but about their frequency per unit of software.
In summary, defect density is a metric used to measure the number of defects found per unit of code or functionality, providing insight into the quality of the software being tested.
Question 159:
What is the primary focus of system testing?
a) To ensure that the software meets functional requirements
b) To test individual units or components of the software
c) To evaluate the system’s performance and scalability
d) To test the system as a whole and ensure it meets the requirements
Answer:
d) To test the system as a whole and ensure it meets the requirements
Explanation:
System testing is a type of testing that focuses on validating the software system as a whole. The primary goal of system testing is to ensure that the entire system meets the specified requirements and functions as expected in an integrated environment. Unlike unit testing, which focuses on individual components, or integration testing, which focuses on verifying interactions between components, system testing evaluates the system in its entirety.
System testing includes various types of tests, such as:
Functional testing: Verifying that the software’s features work according to the defined requirements.
Non-functional testing: Testing attributes such as performance, security, scalability, and usability.
Regression testing: Ensuring that new changes or features do not break existing functionality.
Compatibility testing: Ensuring the system works on different platforms, devices, and browsers.
System testing is conducted in an environment that closely resembles the production environment to ensure that the system will perform correctly when deployed. It is often the final phase of testing before the system is released to end-users or customers.
System testing is crucial because it validates the software as a complete solution and ensures that all components and features work together seamlessly. This type of testing helps identify defects that may not have been discovered during earlier testing stages, such as integration testing or unit testing.
Option a is incorrect because ensuring functional requirements are met is part of functional testing, not system testing as a whole. Option B is incorrect because unit testing focuses on testing individual components, not the entire system. Option C is incorrect because while performance testing is part of system testing, the primary focus of system testing is to ensure the system meets all requirements, both functional and non-functional, as a whole.
In summary, system testing focuses on testing the entire system as a whole to ensure it meets the specified requirements and works correctly in an integrated environment.
Question 160:
Which of the following is an example of a non-functional requirement?
a) The system should allow users to log in with a username and password
b) The system should provide search functionality
c) The system should be able to handle 500 concurrent users
d) The system should generate weekly reports for administrators
Answer:
c) The system should be able to handle 500 concurrent users
Explanation:
Non-functional requirements (NFRs) define the quality attributes, performance criteria, and constraints of a system, rather than its specific functionality. These requirements describe how the system should behave rather than what the system should do. Non-functional requirements typically address aspects such as performance, scalability, security, reliability, and usability.
The requirement that “the system should be able to handle 500 concurrent users” is an example of a non-functional requirement because it focuses on the system’s performance and scalability. It specifies a quantitative measure of the system’s ability to handle a certain load, which is a key aspect of non-functional testing. Non-functional requirements ensure that the system can function effectively under various conditions, meet performance benchmarks, and deliver a satisfactory user experience.
Other examples of non-functional requirements include:
Performance: The system must respond to user requests within 2 seconds.
Scalability: The system must support an increase in users or transactions without significant performance degradation.
Security: The system must ensure that sensitive data is encrypted during transmission.
Availability: The system must be available 99.9% of the time.
In contrast, functional requirements define the specific features or behaviors that the system must provide to fulfill user needs. Option a is a functional requirement, as it specifies that users must be able to log in using a username and password. Option B is also a functional requirement, as it describes a specific feature (search functionality) that the system should provide. Option d is a functional requirement as well, specifying a feature that the system must generate reports for administrators.
