ISTQB CT-PT Practice Exams
Last updated on Oct 21,2026- Exam Code: CT-PT
- Exam Name: ISTQB Certified Tester - Performance Testing
- Certification Provider: ISTQB
- Latest update: Oct 21,2026
Question #21
Which of the following is a general principle of performance testing?
- A . Tests must be executable within the project timeframe.
- B . Test results must be comparable to tester expectations.
- C . Test results must vary when the tests are run repeatedly on an unchanged system.
- D . Tests must align with the ideal outcome of stakeholders.
Correct Answer: A
A
Explanation:
Performance testing is time-sensitive and must be designed to fit within the constraints of the project timeline. If performance tests take too long to execute, they may not be feasible within a given sprint or development cycle. The results should be reproducible, meaning the same test on an unchanged system should yield the same results (making option C incorrect). While stakeholder expectations are important, performance tests should be objective and based on defined benchmarks rather than subjective expectations (making option D incorrect).
Reference: ISTQB CT-PT Syllabus, Section 2.1: Principles of Performance Testing.
A
Explanation:
Performance testing is time-sensitive and must be designed to fit within the constraints of the project timeline. If performance tests take too long to execute, they may not be feasible within a given sprint or development cycle. The results should be reproducible, meaning the same test on an unchanged system should yield the same results (making option C incorrect). While stakeholder expectations are important, performance tests should be objective and based on defined benchmarks rather than subjective expectations (making option D incorrect).
Reference: ISTQB CT-PT Syllabus, Section 2.1: Principles of Performance Testing.
Question #22
Which of the following is a key reason to include ramp-up and ramp-down periods in a performance test?
- A . To ensure virtual users complete their transactions within a defined time window
- B . To simulate a more realistic user load pattern and avoid sudden system stress
- C . To provide a buffer for slow-performing transactions to complete
- D . To guarantee that all virtual users remain active throughout the test duration
Correct Answer: B
B
Explanation:
A ramp-up period in a performance test gradually increases load over time, and a ramp-down period does the opposite. This prevents sudden surges in system load, making test results more realistic.
Option A (Ensuring transactions complete in a time window) is incorrect because ramp-up/down periods do not control transaction timing.
Option C (Providing a buffer for slow transactions) is incorrect because ramp-up/down is about load balancing, not transaction timing.
Option D (Keeping all virtual users active throughout the test) is incorrect because ramp-down periods reduce users gradually.
Reference: ISTQB CT-PT Syllabus, Section 3.2.1: Load Profiles and Ramping Strategies.
B
Explanation:
A ramp-up period in a performance test gradually increases load over time, and a ramp-down period does the opposite. This prevents sudden surges in system load, making test results more realistic.
Option A (Ensuring transactions complete in a time window) is incorrect because ramp-up/down periods do not control transaction timing.
Option C (Providing a buffer for slow transactions) is incorrect because ramp-up/down is about load balancing, not transaction timing.
Option D (Keeping all virtual users active throughout the test) is incorrect because ramp-down periods reduce users gradually.
Reference: ISTQB CT-PT Syllabus, Section 3.2.1: Load Profiles and Ramping Strategies.
Question #23
Why is it important to specify how failures are handled during test execution?
- A . To meet the expectations of the business stakeholders
- B . To ensure that new failures are not introduced
- C . To ensure all defects are captured
- D . To minimize distractions during testing
Correct Answer: B
B
Explanation:
During performance testing, it is crucial to define failure handling procedures to ensure that failures do not introduce additional errors into the test execution process. This helps maintain test accuracy and avoid misleading results.
Option A (Meeting stakeholder expectations) is important but not the primary reason for defining failure handling.
Option C (Capturing all defects) is a general testing principle, not specific to failure handling in performance tests.
Option D (Minimizing distractions) is not a valid reason for defining failure handling.
Reference: ISTQB CT-PT Syllabus, Section 4.4: Handling Failures in Performance Testing.
B
Explanation:
During performance testing, it is crucial to define failure handling procedures to ensure that failures do not introduce additional errors into the test execution process. This helps maintain test accuracy and avoid misleading results.
Option A (Meeting stakeholder expectations) is important but not the primary reason for defining failure handling.
Option C (Capturing all defects) is a general testing principle, not specific to failure handling in performance tests.
Option D (Minimizing distractions) is not a valid reason for defining failure handling.
Reference: ISTQB CT-PT Syllabus, Section 4.4: Handling Failures in Performance Testing.
Question #24
Which of the following can provide measurements for both individual and aggregated elements within a single performance test?
- A . Aggregated metrics
- B . Process optimization tracking
- C . Measuring underlying transactions
- D . Nested transactions
Correct Answer: D
D
Explanation:
Nested transactions allow performance tests to capture both individual and aggregated elements by grouping multiple related transactions and measuring their cumulative impact.
Option A (Aggregated metrics) provides summaries but lacks insight into individual elements.
Option B (Process optimization tracking) focuses on business process improvement, not test metrics.
Option C (Measuring underlying transactions) focuses only on individual transactions.
Reference: ISTQB CT-PT Syllabus, Section 2.6: Measuring Individual and Aggregate Performance.
D
Explanation:
Nested transactions allow performance tests to capture both individual and aggregated elements by grouping multiple related transactions and measuring their cumulative impact.
Option A (Aggregated metrics) provides summaries but lacks insight into individual elements.
Option B (Process optimization tracking) focuses on business process improvement, not test metrics.
Option C (Measuring underlying transactions) focuses only on individual transactions.
Reference: ISTQB CT-PT Syllabus, Section 2.6: Measuring Individual and Aggregate Performance.
Question #25
Which of the following is typically the result of oversaturation of system resources during performance testing?
- A . Response time will gradually improve over a period of time.
- B . Response time will be slow under significant load levels.
- C . Error logging will decrease.
- D . The size of the database will gradually decrease.
Correct Answer: B
B
Explanation:
When system resources (e.g., CPU, RAM, I/O) are oversaturated, the system becomes overloaded, leading to increased response times and poor application performance.
Option A (Gradual improvement of response time) is incorrect because performance degrades under heavy load.
Option C (Error logging decreases) is unlikely; in most cases, errors increase when systems reach their limits.
Option D (Database size decreases) is unrelated to performance saturation.
Reference: ISTQB CT-PT Syllabus, Section 2.5: Identifying System Bottlenecks.
B
Explanation:
When system resources (e.g., CPU, RAM, I/O) are oversaturated, the system becomes overloaded, leading to increased response times and poor application performance.
Option A (Gradual improvement of response time) is incorrect because performance degrades under heavy load.
Option C (Error logging decreases) is unlikely; in most cases, errors increase when systems reach their limits.
Option D (Database size decreases) is unrelated to performance saturation.
Reference: ISTQB CT-PT Syllabus, Section 2.5: Identifying System Bottlenecks.
Question #26
At what point during performance testing does monitoring with the load testing tool begin?
- A . When testing is concluded.
- B . Before testing execution.
- C . Immediately after test execution.
- D . Simultaneously with test execution.
Correct Answer: D
D
Explanation:
Performance monitoring must begin simultaneously with test execution to capture system behavior in real-time. This ensures that bottlenecks and performance issues are identified immediately.
Option A (After testing is concluded) is incorrect because historical monitoring does not help in real-time analysis.
Option B (Before execution) is incorrect because monitoring needs active system load to measure performance.
Option C (Immediately after execution) is incorrect because it misses runtime metrics.
Reference: ISTQB CT-PT Syllabus, Section 4.1: Performance Monitoring Best Practices.
D
Explanation:
Performance monitoring must begin simultaneously with test execution to capture system behavior in real-time. This ensures that bottlenecks and performance issues are identified immediately.
Option A (After testing is concluded) is incorrect because historical monitoring does not help in real-time analysis.
Option B (Before execution) is incorrect because monitoring needs active system load to measure performance.
Option C (Immediately after execution) is incorrect because it misses runtime metrics.
Reference: ISTQB CT-PT Syllabus, Section 4.1: Performance Monitoring Best Practices.
Question #27
Which of the following is usually identified by a performance test?
- A . Resource bottlenecks
- B . Suitability issues
- C . Learnability concerns
- D . Failure to meet accessibility requirements
Correct Answer: A
A
Explanation:
Performance tests primarily identify resource bottlenecks such as CPU saturation, memory leaks, network congestion, and database slowdowns.
Option B (Suitability issues) is a functional requirement concern, not a performance issue.
Option C (Learnability concerns) relates to usability testing, not performance.
Option D (Accessibility requirements) falls under compliance and usability testing, not performance testing.
Reference: ISTQB CT-PT Syllabus, Section 2.5: Identifying Bottlenecks and Performance Issues.
A
Explanation:
Performance tests primarily identify resource bottlenecks such as CPU saturation, memory leaks, network congestion, and database slowdowns.
Option B (Suitability issues) is a functional requirement concern, not a performance issue.
Option C (Learnability concerns) relates to usability testing, not performance.
Option D (Accessibility requirements) falls under compliance and usability testing, not performance testing.
Reference: ISTQB CT-PT Syllabus, Section 2.5: Identifying Bottlenecks and Performance Issues.
Question #28
You are heading the testing effort for a system that manages the air/fuel ratio of direct-injection fuel devices built specifically for high-altitude rescue helicopter engines. At altitude, the system must be able to perform in order to make enough air/fuel ratio adjustments per millisecond between fuel and both an on-board source and available ambient air in order to prevent an engine stall due to oxygen starvation. The system is following a sequential development lifecycle.
For this safety-critical software, when is the appropriate point in the lifecycle to identify and define the performance goals?
- A . After test readiness has been achieved, but before system testing starts
- B . During the requirements phase when the business stakeholders have the opportunity to agree
- C . At the very beginning of the project during the concept stage
- D . During the software design phase when the requirements are set and the design is being defined
Correct Answer: B
B
Explanation:
For safety-critical software, performance goals must be identified as early as the requirements phase. This ensures that performance constraints are well understood and accounted for throughout development.
Option A (After test readiness but before system testing) is too late, as requirements should be defined before coding begins.
Option C (During the concept stage) is too early, as details may not be concrete.
Option D (During software design) is useful but should be preceded by a proper definition during the requirements phase.
Reference: ISTQB CT-PT Syllabus, Section 1.2: Defining Performance Goals Early.
B
Explanation:
For safety-critical software, performance goals must be identified as early as the requirements phase. This ensures that performance constraints are well understood and accounted for throughout development.
Option A (After test readiness but before system testing) is too late, as requirements should be defined before coding begins.
Option C (During the concept stage) is too early, as details may not be concrete.
Option D (During software design) is useful but should be preceded by a proper definition during the requirements phase.
Reference: ISTQB CT-PT Syllabus, Section 1.2: Defining Performance Goals Early.
Question #29
Which of the following should be a key part of your test acceptance criteria in your performance test plan?
- A . Convincing technical and business stakeholders to provide realistic performance goals for the regional servers
- B . Describing the system under test in order to provide context to the metrics
- C . Highlighting any technical differences in the hardware between the test environment and the production environment
- D . Documenting previously baselined performance metrics in order to compare these to the new performance measurements
Correct Answer: C
C
Explanation:
One of the most critical test acceptance criteria in performance testing is to ensure that the hardware in the test environment is comparable to production. Differences in CPU, memory, disk I/O, or network infrastructure can distort performance results.
Option A (Convincing stakeholders to set goals) is a planning activity, not an acceptance criterion.
Option B (Describing the system under test) is important but does not directly affect test acceptance.
Option D (Comparing baselined metrics) is useful, but without a comparable test environment, baseline metrics may be misleading.
Reference: ISTQB CT-PT Syllabus, Section 1.5: Test Acceptance Criteria.
C
Explanation:
One of the most critical test acceptance criteria in performance testing is to ensure that the hardware in the test environment is comparable to production. Differences in CPU, memory, disk I/O, or network infrastructure can distort performance results.
Option A (Convincing stakeholders to set goals) is a planning activity, not an acceptance criterion.
Option B (Describing the system under test) is important but does not directly affect test acceptance.
Option D (Comparing baselined metrics) is useful, but without a comparable test environment, baseline metrics may be misleading.
Reference: ISTQB CT-PT Syllabus, Section 1.5: Test Acceptance Criteria.
Question #30
What challenge must be considered when using crowds to emulate load generation?
- A . The load generation will be difficult to reproduce.
- B . The load generation method is less sensitive to changes in the system under test.
- C . This type of load generation is more suitable for mainframe applications.
- D . This technique is more precise than other methods of load generation.
Correct Answer: A
A
Explanation:
Crowd-based load generation relies on real users from different locations, making test conditions highly variable. This makes it difficult to reproduce the same test scenario multiple times under identical conditions.
Option B (Less sensitive to changes) is incorrect because crowd-based load is highly sensitive to external conditions (network, device types, etc.).
Option C (Suitable for mainframe applications) is incorrect because crowd-based load testing is typically used for web and cloud applications, not mainframes.
Option D (More precise than other methods) is incorrect because crowd-based load testing lacks precision due to real-world inconsistencies.
Reference: ISTQB CT-PT Syllabus, Section 3.1.2: Challenges in Load Generation Approaches.
A
Explanation:
Crowd-based load generation relies on real users from different locations, making test conditions highly variable. This makes it difficult to reproduce the same test scenario multiple times under identical conditions.
Option B (Less sensitive to changes) is incorrect because crowd-based load is highly sensitive to external conditions (network, device types, etc.).
Option C (Suitable for mainframe applications) is incorrect because crowd-based load testing is typically used for web and cloud applications, not mainframes.
Option D (More precise than other methods) is incorrect because crowd-based load testing lacks precision due to real-world inconsistencies.
Reference: ISTQB CT-PT Syllabus, Section 3.1.2: Challenges in Load Generation Approaches.