<< Chapter < Page
  Software engineering     Page 7 / 15
Chapter >> Page >

Good partitioning requires knowledge of the software structure. A good testing plan will not only contain black-box testing, but also white-box approaches, and combinations of the two.

White-box testing

Contrary to black-box testing, software is viewed as a white-box, or glass-box in white-box testing, as the structure and flow of the software under test are visible to the tester. Testing plans are made according to the details of the software implementation, such as programming language, logic, and styles. Test cases are derived from the program structure. White-box testing is also called glass-box testing, logic-driven testing or design-based testing.

There are many techniques available in white-box testing, because the problem of intractability is eased by specific knowledge and attention on the structure of the software under test. The intention of exhausting some aspect of the software is still strong in white-box testing, and some degree of exhaustion can be achieved, such as executing each line of code at least once (statement coverage), traverse every branch statements (branch coverage), or cover all the possible combinations of true and false condition predicates (Multiple condition coverage).

Control-flow testing, loop testing, and data-flow testing, all maps the corresponding flow structure of the software into a directed graph. Test cases are carefully selected based on the criterion that all the nodes or paths are covered or traversed at least once. By doing so we may discover unnecessary "dead" code - code that is of no use, or never get executed at all, which can not be discovered by functional testing.

In mutation testing, the original program code is perturbed and many mutated programs are created, each contains one fault. Each faulty version of the program is called a mutant. Test data are selected based on the effectiveness of failing the mutants. The more mutants a test case can kill, the better the test case is considered. The problem with mutation testing is that it is too computationally expensive to use. The boundary between black-box approach and white-box approach is not clear-cut. Many testing strategies mentioned above, may not be safely classified into black-box testing or white-box testing. It is also true for transaction-flow testing, syntax testing, finite-state testing, and many other testing strategies not discussed in this text. One reason is that all the above techniques will need some knowledge of the specification of the software under test. Another reason is that the idea of specification itself is broad - it may contain any requirement including the structure, programming language, and programming style as part of the specification content.

We may be reluctant to consider random testing as a testing technique. The test case selection is simple and straightforward: they are randomly chosen. Random testing is more cost effective for many programs. Some very subtle errors can be discovered with low cost. And it is also not inferior in coverage than other carefully designed testing techniques. One can also obtain reliability estimate using random testing results based on operational profiles. Effectively combining random testing with other testing techniques may yield more powerful and cost-effective testing strategies.

Questions & Answers

draw and explain state and activity diagram of library management system
Prashant Reply
explain association and generalisation with library system diagram
Prashant Reply
what do you mean by functional and non functional requirements
functional - describes what a software system should do . non functional - place constraints on how the will do so
non functional requirement include: quility . reliability . response time . security . privacy . effectiveness . maintainability . robustness scalability . fault tolerance . extensibility . efficiency . portability . resilience ... .
What does encapsulation mean?
Sravanthi Reply
Encapsulation in Java is a process of wrapping code and data together into a single unit, for example, a capsule which is mixed of several medicines. ... Now we can use setter and getter methods to set and get the data in it. The Java Bean class is the example of a fully encapsulated class.
What is software Engineering
Jakisay Reply
Sofyware engineering is the application of principles used in the field of engineering which usually deals with phsical systems to the design, testing, development, deployment and management of software systems
what is cocomo model
Shrudhi Reply
The Constructive Cost Model is a procedural software cost estimation model developed by Barry W. Boehm. The model parameters are derived from fitting a regression formula using data from historical projects
Please is there any scholarship for African students undergraduate for now
Awal Reply
4 generation technology
Richa, what is your question?
what is the work of software engineer
mercy Reply
steps of developing a software
latest Reply
bamori project
which approach used to reduce number of test cases
Harshdeep Reply
I wish to ask what is the mean of a data model
Ateke Reply
explanation of working of computer
Gulfam Reply
How are u guys
What is software engineering
parfait Reply
explain basic path testing for triangle problem?
Janavi Reply

Get the best Software engineering course in your pocket!

Source:  OpenStax, Software engineering. OpenStax CNX. Jul 29, 2009 Download for free at http://cnx.org/content/col10790/1.1
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Software engineering' conversation and receive update notifications?