Statement coverage is a structural coverage metric that measures the percentage of executable statements in the source code that are executed by a test suite1. Decision coverage is another structural coverage metric that measures the percentage of decision outcomes (such as branches or conditions) in the source code that are executed by a test suite1. Decision coverage is a stronger metric than statement coverage, because it requires that every possible outcome of each decision is tested, while statement coverage only requires that every statement is executed at least once2. Therefore, if a test suite achieves 100% decision coverage, it also implies that it achieves 100% statement coverage, because every statement in every branch or condition must have been executed. However, the converse is not true: 100% statement coverage does not guarantee 100% decision coverage, because some branches or conditions may have multiple outcomes that are not tested by the test suite2. For example, consider the following pseudocode:
if (x > 0) then print("Positive") else print("Non-positive") end if
A test suite that executes this code with x = 1 and x = -1 will achieve 100% statement coverage, because both print statements are executed. However, it will not achieve 100% decision coverage, because the condition x >
0 has only been tested with two outcomes: true and false. The third possible outcome, x = 0, has not been tested by the test suite. Therefore, the test suite may miss a potential bug or error in the condition or the branch.
The other options, such as stale transition coverage, equivalence class coverage, and boundary value coverage, are not guaranteed to be 100% by achieving 100% decision coverage. Stale transition coverage is a structural coverage metric that measures the percentage of transitions between states in a state machine that are executed by a test suite3. Equivalence class coverage is a functional coverage metric that measures the percentage of equivalence classes (or partitions) of input or output values that are tested by a test suite4. Boundary value coverage is another functional coverage metric that measures the percentage of boundary values (or extreme values) of input or output ranges that are tested by a test suite4. These metrics are independent of decision coverage, because they are based on different aspects of the system under test, such as its behavior, functionality, or specification. Therefore, achieving 100% decision coverage does not imply achieving 100% of any of these metrics, and vice versa. References = ISTQB Certified Tester Foundation Level Syllabus v4.0, Test Coverage in Software Testing - Guru99, Structural Coverage Metrics - MATLAB & Simulink - MathWorks India, Test Design Coverage in Software Testing - GeeksforGeeks.

The testing of software does not demonstrate the absence of defects, but rather the presence of defects or the conformance of the software to the specified requirements1. Testing can never prove that the software is defect-free, as it is impossible to test all possible scenarios, inputs, outputs, and behaviors of the software2. Testing can only provide a level of confidence in the quality of the software, based on the coverage, effectiveness, and efficiency of the testing activities3.
The other options are correct because:
A) Properly designed tests that pass reduce the level of risk in a system, as they verify that the system meets the expected quality attributes and satisfies the needs and expectations of the users and clients4. Risk is the potential for loss or harm due to the occurrence of an undesirable event5. Testing can help to identify, analyze, prioritize, and mitigate the risks associated with the software product and project6.
C) Software testing identifies defects, which can be used to improve development activities, as they provide feedback on the quality of the software and the effectiveness of the development processes7. Defects are flaws or errors in the software that cause it to deviate from the expected or required results or behavior. Testing can help to detect, report, track, and resolve the defects, and prevent them from recurring in the future.
D) Performing a review of the requirement specifications before implementing the system can enhance quality, as it can ensure that the requirements are clear, complete, consistent, testable, and aligned with the needs and expectations of the users and clients. Requirements are the specifications of what the software should do and how it should do it. Testing can help to validate that the requirements are met by the software, and verify that the software is implemented according to the requirements.
Reference =
1 ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 10
2 ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 11
3 ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 12
4 ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 13
5 ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 97
6 ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 98
7 ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 14
[8] ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 15
[9] ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 16
[10] ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 17
[11] ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 18
[12] ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 19

The ISTQB fundamental test process consists of five main phases, as described in the ISTQB Foundation Level Syllabus, Version 4.0, 2018, Section 2.2, page 15:
* Test planning and control: This phase involves defining the test objectives, scope, strategy, resources, schedule, risks, and metrics, as well as monitoring and controlling the test activities and results throughout the test process.
* Test analysis and design: This phase involves analyzing the test basis (such as requirements, specifications, or user stories) to identify test conditions (such as features, functions, or scenarios) that need to be tested, and designing test cases and test procedures (such as inputs, expected outcomes, and execution steps) to cover the test conditions. This phase also involves evaluating the testability of the test basis and the test items (such as software or system components), and selecting and implementing test techniques (such as equivalence partitioning, boundary value analysis, or state transition testing) to achieve the test objectives and optimize the test coverage and efficiency.
* Test implementation and execution: This phase involves preparing the test environment (such as hardware, software, data, or tools) and testware (such as test cases, test procedures, test data, or test scripts) for test execution, and executing the test procedures or scripts according to the test plan and schedule. This phase also involves logging the outcome of test execution, comparing the actual results with the expected results, and reporting any discrepancies as incidents (such as defects, errors, or failures).
* Evaluating exit criteria and reporting: This phase involves checking if the planned test activities have been completed and the exit criteria (such as quality, coverage, or risk levels) have been met, and reporting the test results and outcomes to the stakeholders. This phase also involves making recommendations for the release or acceptance decision based on the test results and outcomes, and identifying any residual risks (such as known defects or untested areas) that need to be addressed or mitigated.
* Test closure activities: This phase involves finalizing and archiving the testware and test environment for future reuse, and evaluating the test process and the test project against the test objectives and the test plan. This phase also involves identifying any lessons learned and best practices, and communicating the findings and suggestions for improvement to the relevant parties.
References = ISTQB Certified Tester Foundation Level Syllabus, Version 4.0, 2018, Section 2.2, page 15; ISTQB Glossary of Testing Terms, Version 4.0, 2018, pages 37-38; ISTQB CTFL 4.0 - Sample Exam - Answers, Version 1.1, 2023, Question 88, page 32.

This answer is correct because equivalence partitioning is a test design technique that divides the input domain of a system or component into partitions of equivalent data, such that each partition is expected to produce the same output or behavior. Equivalence partitioning aims to reduce the number of test cases by selecting one representative value from each partition. In this case, the input domain of the TAS can be divided into four partitions based on the bonus rules: less than 50k€, between 50k€ and 80k€, between 80k€ and 120k€, and more than 120k€. The test cases in the answer belong to the same partition, which is between 80k€ and 120k€, and they are expected to produce the same output, which is a bonus of 15%. References: ISTQB Glossary of Testing Terms v4.0, ISTQB Foundation Level Syllabus v4.0, Section 2.3.2.1

* Effort estimate does not depend on the budget of the project, but rather on the scope, complexity, and quality of the software product and the testing activities1. Budget is a constraint that may affect the feasibility and accuracy of the effort estimate, but it is not a factor that determines the effort estimate. Effort estimate is the amount of work required to complete the testing activities, measured in terms of person-hours, person-days, or person-months2.
* The other options are correct because:
* A. Once the test effort is estimated, resources can be identified and a schedule can be drawn up, as they are interrelated aspects of the test planning process3. Resources are the people, tools, equipment, and facilities needed to perform the testing activities4. Schedule is the time frame and sequence of the testing activities, aligned with the project milestones and deadlines5.
* B. Effort estimate can be inaccurate because the quality of the product under tests is not known, as it affects the number and severity of the defects that may be found and the rework that may be needed to fix them6. Quality is the degree to which the software product satisfies the specified requirements and meets the needs and expectations of the users and clients7.
* D. Experience based estimation is one of the estimation techniques, which relies on the judgment and expertise of the testers and other project stakeholders to estimate the test effort based on similar projects or tasks done in the past. Experience based estimation can be useful when there is a lack of historical data, formal methods, or detailed information about the software product and the testing activities.
References =
* 1 ISTQB Certified Tester Foundation Level Syllabus v4.0, 2023, p. 154
* 2 ISTQB Certified Tester Foundation Level Syllabus v4.0, 2023, p. 155
* 3 ISTQB Certified Tester Foundation Level Syllabus v4.0, 2023, p. 156
* 4 ISTQB Certified Tester Foundation Level Syllabus v4.0, 2023, p. 157
* 5 ISTQB Certified Tester Foundation Level Syllabus v4.0, 2023, p. 158
* 6 ISTQB Certified Tester Foundation Level Syllabus v4.0, 2023, p. 159
* 7 ISTQB Certified Tester Foundation Level Syllabus v4.0, 2023, p. 16
* [8] ISTQB Certified Tester Foundation Level Syllabus v4.0, 2023, p. 160
* [9] ISTQB Certified Tester Foundation Level Syllabus v4.0, 2023, p. 161