2.2 Test levels and test types

Question 1

What are test levels?

Answer 1

groups of test activities that are organised and managed together
Each test level is an instance of the test process, performed in relation to software at a given stage of development, from individual components to complete systems or, where applicable, systems of systems.

Question 2

How are test levels related to each other?

Answer 2

the test levels are often defined such that the exit criteria of one level are part of the entry criteria for the next level
In some iterative models, this may not apply. Development activities may span through multiple test levels. Test levels may overlap in time.

Question 3

What are test types?

Answer 3

groups of test activities related to specific quality characteristics and most of those test activities can be performed at every test level.

Question 4

What are the five test levels?

Answer 4

1. Component testing / Unit testing
2. Component (unit) integration testing
3. System testing
4. System integration testing
5. Acceptance testing

Question 5

What is component testing?

Answer 5

(also known as unit testing) focuses on testing components in isolation. It often requires specific support, such as test harnesses or unit test frameworks.

Question 6

Who performs component testing?

Answer 6

normally performed by developers in their development environments

Question 7

What is component integration testing?

Answer 7

focuses on testing the interfaces and interactions between components. Component integration testing is heavily dependent on the integration strategy approaches like bottom-up, top-down or big-bang

Question 8

What is system testing?

Answer 8

focuses on the overall behavior and capabilities of an entire system or product, often including functional testing of end-to-end tasks and the non-functional testing of quality characteristics.

Question 9

What type of environment do you perform system testing?

Answer 9

representative test environment (e.g., usability). Using simulations of sub-systems is also possible

Question 10

What is system integration testing?

Answer 10

focuses on testing the interfaces of the system under test and other systems and external services . System integration testing requires suitable test environments preferably similar to the operational environment.

Question 11

What is acceptance testing?

Answer 11

focuses on validation and on demonstrating readiness for deployment, which means that the system fulfills the user’s business needs.

Question 12

Who should perform acceptance testing?

Answer 12

Ideally, acceptance testing should
be performed by the intended users

Question 13

What are the main forms of acceptance testing?

Answer 13

user acceptance testing (UAT)
operational acceptance testing
contractual and regulatory acceptance testing,
alpha testing
beta testing.

Question 14

How are test levels distinguished?

Answer 14

by the following non-exhaustive list of attributes, to avoid overlapping of test activities:
* Test object
* Test objectives
* Test basis
* Defects and failures
* Approach and responsibilities

Question 15

What are the four test types?

Answer 15

Functional testing
Non-functional testing
Black-box testing
white-box testing

Question 16

What is functional testing?

Answer 16

evaluates the functions that a component or system should perform. The functions are “what” the test object should do. The main objective of functional testing is checking the functional completeness, functional correctness and functional appropriateness

Question 17

What is non-functional testing?

Answer 17

evaluates attributes other than functional characteristics of a component or system. Non-functional testing is the testing of “how well the system behaves”. The main objective of nonfunctional testing is checking the non-functional software quality characteristics.

Question 18

Which standard provides the classification of non-functional software quality?

Answer 18

ISO/IEC 25010

Question 19

What non-functional quality standards does the ISO/IEC 25010 specify?

Answer 19

• Performance efficiency
• Compatibility
• Usability
• Reliability
• Security
• Maintainability
• Portability

Question 20

What is black-box testing?

Answer 20

specification-based and derives tests from documentation external to the test object. The main objective of black-box testing is checking the system’s behavior against its specifications.

Question 21

What is white box testing?

Answer 21

structure-based and derives tests from the system’s implementation or internal structure (e.g., code, architecture, work flows, and data flows). The main objective of white-box testing is to cover the underlying structure by the tests to the acceptable level.

Question 22

What is confirmation testing?

Answer 22

confirms that an original defect has been successfully fixed. Depending on the risk, one can test the fixed version of the software in several ways, including:
* executing all test cases that previously have failed due to the defect, or, also by
* adding new tests to cover any changes that were needed to fix the defect

Question 23

When time or money is short, how might confirmation testing be restricted?

Answer 23

simply exercising the steps that should reproduce the failure caused by the defect and checking that the failure does not occur.

Question 24

What is regression testing?

Answer 24

confirms that no adverse consequences have been caused by a change, including a
fix that has already been confirmation tested. These adverse consequences could affect the same component where the change was made, other components in the same system, or even other connected systems.

Question 25

How would you optimise the extent of regression testing?

Answer 25

Perform an impact analysis to optimise the extent of regression testing

Question 26

Why is regression testing a strong candidate for automated tests?

Answer 26

• Regression test suites are run many times
• generally the number of regression test cases will increase with each iteration or release