Regarding terminology, I don’t have a single source handy that uses the exact terms “basic condition coverage” and “multiple condition coverage“. Binder’s “Testing Object-Oriented Systems” says “condition coverage” and “multiple-condition coverage”. Everett & McLeod’s “Software Testing” says “simple condition coverage” and “compound condition coverage”. But I’m certain that the first term in each case is your “basic condition coverage” and the second is your “compound condition coverage”. The modified condition/decision coverage (MC/DC) coverage is like condition coverage, but every condition in a decision must be tested independently to reach full coverage.
That the design logically isolates the safety-critical design elements and data from those that are non-safety-critical. Confirm that the values of the safety-critical loaded data, uplinked data, rules, and scripts that affect hazardous system behavior have been tested. This analysis includes an assessment of any identified issues found during use in the previous system and implementation of all preconditions for its use in the new system. Connect and share knowledge within a single location that is structured and easy to search.
Example Code with 1 condition
White Box Testing is also known as transparent testing or open box testing. – White box – White-box techniques (also called structural or structure-based techniques) are based on an analysis of the internal structure of the component or system. Percentage of combinations of all single condition outcomes within one and the same operator that have been tested by a set of tests. 100% multiple condition coverage presupposes 100% condition determination coverage. White box testing is a software testing technique that involves testing the internal structure and workings of a software application. The tester has access to the source code and uses this knowledge to design test cases that can verify the correctness of the software at the code level.
According to Multiple Condition Coverage criteria, all combinations of True and False values of conditions must be covered. In any decision, there are some possible number of conditions, which can be examined and evaluated by applying Boolean Expression as expressed above. For MC/DC it is required, that each condition has to affect the outcome independently. With the above test (all are 0 or all are 1), we ignore the fact, that c-value doesn’t matter if a and b are 0, or, that b-value doesnt matter if a and c are 1. Where conflicts with program safety requirements exist, program safety requirements take precedence.
Multiple Condition Coverage (MCC) in software testing
The design has a better chance of being implemented as needed to meet the requirements in an elegant, simple, and reliable way. MC/DC testing should be performed during unit test phase and should ensure that the software unit behaves as required/expected as well as all meaningful conditional paths through the code are exercised. A specific type of cyclomatic complexity is not required, it is up to the individual projects to determine if they should use strict, normal, or modified.
- In case the decision is a condition (i.e. just a), that is also called basic condition coverage, which is the coverage of the two branches of a single condition.
- Decisions are the controls that can control the program flow after evaluating the full expression.
- Anything less than MCDC exposes a risk of a safety-critical decision based on a set of conditions not being tested.
- Whether or not one is more efficient than the other depends on the language being used.
- The first step analyzes the test cases about the software requirements to confirm that the selected test cases satisfy the specified criteria.
- I might be missing something here but, the way you wrote the code in your question, conditions A and B are completely independent of each other.
In MCDC each condition should be evaluated at least once which affects the decision outcome independently. – The chief disadvantage of statement coverage is that it is insensitive to some control structures. In Multiple Condition Coverage for each decision all the combinations of conditions should be evaluated. This would seem to indicate that Multiple Condition Coverage, as the name suggests, only applies to conditionals with multiple statements. When using the White Box method of testing called Multiple Condition Coverage, do we take all conditional statements or just the ones with multiple conditions?
Decision Coverage or Branch Coverage
MC/DC requires a much smaller number of test cases than multiple condition coverage (MCC) while retaining a high error-detection probability. A less aggressively optimized set of test cases for basic condition coverage would have one test case where all three basic conditions are false and three test cases with a different basic condition true in each. That would still only be four of the eight possible combinations of basic conditions in the compound condition. The uncomfortable feeling that we’re ignoring the other four is why there’s compound condition coverage. That requires a test for each possible combination of basic conditions in a compound condition.
In the example above, you’d need eight tests, one for each possible combination of possible values of a, b and c, to get full compound condition coverage. Test coverage analysis can be considered a two-step process involving requirements-based coverage analysis and structural coverage analysis. The first step analyzes the test cases about the software requirements to confirm that the selected test cases satisfy the specified criteria. The second step ensures that the requirements-based test procedures exercised the code structure to the applicable coverage criteria. This requires that when testing a safety-critical computing system safety item, its validation and verification must include testing by a test team. This validation and verification should take place within the development cycle and contribute iterative findings to the design of the computing system safety item.
The project must validate and verify the safety requirements for reused computing system safety items. In addition, a project must validate and verify the safety requirements for third-party products. Using previously developed computing system safety items can reduce development time, because those components have already undergone design and testing. However, analysis of accidents where software was a contributing factor shows the risks in this approach. For a full example of MC/DC testing coverage, see section 7.21 “Multi-condition Software Requirements”.
However for MCDC the above test cases are not sufficient because in MCDC each Boolean variable should be evaluated to TRUE and FALSE at least once and also affect the decision outcome. Decisions are the controls that can control the program flow after evaluating the full expression. The building blocks of TMAP give you all the guidance you need to meet the testing and quality challenges in your specific information technology environment. This requirement applies to all Class A, B, C, and D projects that have safety-critical software regardless of size.
White box testing Simplified
A unit test tool can be utilized to identify or generate tests to adhere to MC/DC criterion . The developer should ensure that the unit is functioning as expected. I might be missing something here but, the way you wrote the code in your question, conditions A and B are completely independent of each other.
All Safety-critical software decisions must be tested to protect against loss of crew or vehicle. MCDC testing represents the minimal set of tests necessary to achieve test coverage over decisions that change the behavior/outcome/output of a computer program. Anything less than MCDC exposes a risk of a safety-critical decision based on a set of conditions not being tested. Aerospace and space guidance prioritizes safety above all else in the software development life cycle. MC/DC represents a compromise that finds a balance between rigor and effort, positioning itself between decision coverage (DC) and multiple condition coverage (MCC).
Multiple condition coverage MCC
In case the decision is a condition (i.e. just a), that is also called basic condition coverage, which is the coverage of the two branches of a single condition. There is a compound condition, a && b && c, with three basic conditions, a, b and c. It takes only two test cases, one where all basic https://www.globalcloudteam.com/ conditions are true and one where all are false, to get full basic condition coverage. It doesn’t matter that the basic conditions happen to be part of a compound condition. C, those two test cases above would still achieve basic condition coverage but would not achieve branch coverage.