Page 211 - DCAP405_SOFTWARE_ENGINEERING

Software Engineering

Notes

Notes Errors are much more common in the neighbourhood of logical conditions than
they are in the locus of the sequential processing.
Cyclomatic complexity provides the upper bound on the number of test cases that must be
executed to guarantee that every statement in a component has been executed at least once.

Self Assessment

Fill in the blanks:
1. Test cases are derived from the ……………………. structure.
2. An independent path is any path through the program that introduces at least one new set
of processing ……………………. or a new condition.
3. White box testing can test paths within a unit, paths between units during…………………….,
and between subsystems during a system level test.
4. …………………… complexity is software metric that provides a quantitative measure of
the logical complexity of a program.

5. Logic errors and incorrect assumptions are ………………………. proportional to the
probability that a program path will be executed.
6. Testing plans are made according to the details of the software……………………...

7. While white-box testing can be applied at the unit, integration and …………………….. of
the software testing process, it is usually done at the unit level.

12.2 Black-box Testing

Black-box testing or behavioral testing, mainly focuses on the functional requirements of the
software. It enables the software engineer to develop a set of inputs that can fully involve all the
functional requirements for a program. It is not an alternative approach to white-box testing.
Rather, it completes the testing by uncovering different types of errors than the white-box
approach.
Figure 12.4: Black-box Testing

Input test data System Output test data

This approach attempts to find errors in the following categories:
1. incorrect or missing functions,
2. interface related errors,

3. errors in data structures or database accesses,
4. performance related errors and
5. initialization and termination errors.
Black box testing is a software testing techniques in which functionality of the software under
test (SUT) is tested without looking at the internal code structure, implementation details and
knowledge of internal paths of the software.

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