Appraoches Study in details

1. Presented by :- Miss Pragati khade
Dada Patil Mahavidyalaya Karjat

2. Introduction
A strategy for software testing integrates software test case
design methods into a Series of steps that result in the successful
development
A testing is a set of activities that can be planned in advance and
Conducted systematically . A number of Software Testing
approaches have been Proposed .
Characteristics of Software Testing Approaches
1 To perform effectieve Testing .
2 Testing Begins at componenet level and works forward the
integration of entire computer based system .
3 Different Testing Techniques are appropriate at different
Points in time .

3. 4. Testing is conducted by the developer of the software and an
independent test group .
5. Debugging though different from testing must eb included in
any testing strategy .
Software Testing Strategy
The Software Process can be viewed as spiral .

6. UNIT TESTING
IT is a type of software testing where individual units
or components of a software are tested.
The purpose is to validate that each unit of the
software code performs as expected.
Unit Testing is done during the development (coding
phase) of an application by the developers.
Unit Tests isolate a section of code and verify its
correctness.
A unit may be an individual function, method,
procedure, module, or object.

7. In SDLC, STLC, V Model, Unit testing is first level of testing done
before integration testing.
Unit testing is a WhiteBox testing technique that is usually
performed by the developer.

12. Unit Testing LifeCyle:

13. INTEGRATION TESTING
It is defined as a type of testing where software modules
are integrated logically and tested as a group.
A typical software project consists of multiple software
modules, coded by different programmers.
The purpose of this level of testing is to expose defects in
the interaction between these software modules when they are
integrated Integration Testing focuses on checking data
communication amongst these modules.
Hence it is also termed as 'I & T' (Integration and
Testing), 'String Testing' and sometimes 'Thread Testing'.

16. Software Engineering defines variety of strategies to execute
Integration testing, viz.
 Big Bang Approach :
Incremental Approach: which is further divided into the
following
1. Top Down Approach
2. Bottom Up Approach
3. Sandwich Approach - Combination of Top Down and
Bottom Up

17. Big Bang Testing
Big Bang Testing is an Integration testing approach in which all
the components or modules are integrated together at once and
then tested as a unit.
This combined set of components is considered as an
entity while testing.
If all of the components in the unit are not completed,
the integration process will not execute.
Advantages:
Convenient for small systems.

18. Disadvantages:
1. Fault Localization is difficult.
2. Given the sheer number of interfaces that need to be tested in
this approach, some interfaces link to be tested could be
missed easily.
3. Since the Integration testing can commence only after "all" the
modules are designed, the testing team will have less time for
execution in the testing phase.
4. Since all modules are tested at once, high-risk critical modules
are not isolated and tested on priority. Peripheral modules
which deal with user interfaces are also not isolated and
tested on priority.

19. Incremental Testing
In the Incremental Testing approach, testing is done by
integrating two or more modules that are logically related to
each other and then tested for proper functioning of the
application.
Then the other related modules are integrated
incrementally and the process continues until all the logically
related modules are integrated and tested successfully.
Incremental Approach, in turn, is carried out by two different
Methods:
- Bottom Up
-Top Down

20. Top-down Integration Testing
Top Down Integration Testing is a method in which
integration testing takes place from top to bottom following the
control flow of software system.
The higher level modules are tested first and then lower
level modules are tested and integrated in order to check the
software functionality.
Stubs are used for testing if some modules are not ready.

22. Advantages:
1. Fault Localization is easier.
2. Possibility to obtain an early prototype.
3. Critical Modules are tested on priority; major design flaws
could be found and fixed first.
Disadvantages:
1. Needs many Stubs.
2. Modules at a lower level are tested inadequately.

23. Bottom-up Integration Testing
Bottom-up Integration Testing is a strategy in which
the lower level modules are tested first.
These tested modules are then further used to
facilitate the testing of higher level modules.
The process continues until all modules at top level
are tested.
Once the lower level modules are tested and
integrated, then the next level of modules are formed.

25. Advantages:
1. Fault localization is easier.
2. No time is wasted waiting for all modules to be developed
unlike Big-bang approach
Disadvantages:
1. Critical modules (at the top level of software architecture)
which control the flow of application are tested last and
may be prone to defects.
2. An early prototype is not possible

26. S.No. TOP DOWN APPROACH BOTTOM UP APPROACH
1.
In this approach We focus on
breaking up the problem into
smaller parts.
In bottom up approach, we
solve smaller problems and
integrate it as whole and
complete the solution.
2.
Mainly used by structured
programming language such as
COBOL, Fortran, C, etc.
Mainly used by object
oriented programming
language such as C++, C#,
Python.
3.
Each part is programmed
separately therefore contain
redundancy.
Redundancy is minimized by
using data encapsulation and
data hiding.
4.
In this the communications is
less among modules.
In this module must have
communication.

27. 5.
It is used in debugging,
module documentation, etc.
It is basically used in testing.
6.
In top down approach,
decomposition takes place.
In bottom up approach
composition takes place.
7.
In this top function of system
might be hard to identify.
In this sometimes we can not
build a program from the piece
we have started.
8.
In this implementation details
may differ.
This is not natural for people to
assemble.

28. Sandwich Testing
Sandwich Testing is the combination of bottom-up approach and top-down
approach, so it uses the advantage of both bottom up approach and top down
approach.
Initially it uses the stubs and drivers where stubs simulate the behaviour ogf
missing component. It is also known as the Hybrid Integration Testing.

29. Strategy used in Sandwich Testing:
1.It combines both top down and bottom up strategies.
2 .Sandwich testing is basically viewed as 3 layers:
(i) Main target layer
(ii) A layer above the target layer
(iii) A layer below the target layer
3 .In sandwich testing, testing is mainly focused for main target layer. This testing is
selected on the basis of system characteristics and structure’s code.
4. It tries to minimize the number of hubs and drivers when there are more than 3 layers.

30. How to perform Sandwich Testing?
There are 3 simple steps to perform sandwich testing which are given
below.
1 .Test the user interface in isolation using stubs.
2. Test the very lowest level functions by using drivers.
3. When the complete system is in integrated only main target (middle)
layer is remains for final test.

31. Advantage of Sandwich Testing:
Sandwich Testing approach is used in very large projects having sub projects.
It allows parallel testing.
Sandwich testing is time saving approach.
sandwich testing performs more coverage with same stubs.
Disadvantage of Sandwich Testing:
Sandwich Testing is very costly.
Sandwich Testing can not be used for such systems which have a lot of
interdependence between different modules.
In sandwich testing the need of stubs and drivers is very high.

32. Software Testing Technique

34. White Box Testing is software testing technique in which
internal structure, design and coding of software are
tested to verify flow of input-output and to improve
design, usability and security.
In white box testing, code is visible to testers so it is also
called Clear box testing, Open box testing, Transparent box
testing, Code-based testing and Glass box testing.
It is one of two parts of the Box Testing approach to
software testing.

35. The testing can be done at system, integration and unit levels of
software development. One of the basic goals of white box
testing is to verify a working flow for an application.

36. Code optimization by finding hidden errors.
White box tests cases can be easily automated.
Testing is more thorough as all code paths are usually covered.
Testing can start early in SDLC even if GUI is not available.

37. White box testing can be quite complex and expensive.
Developers who usually execute white box test cases detest it.
 The white box testing by developers is not detailed can lead to
production errors.
White box testing requires professional resources, with a
detailed understanding of programming and implementation.
White-box testing is time-consuming, bigger programming
applications take the time to test fully.

40. Black Box Testing
Black Box Testing is a software testing method
in which the functionalities of software applications
are tested without having knowledge of internal code
structure, implementation details and internal paths.
Black Box Testing mainly focuses on input and
output of software applications and it is entirely
based on software requirements and specifications.
It is also known as Behavioral Testing.

41. Advantages Disadvantages
Well suited and efficient for large
code segments.
Limited coverage, since only a
selected number of test scenarios is
actually performed.
Code access is not required. Inefficient testing, due to the fact
that the tester only has limited
knowledge about an application.
Clearly separates user's perspective
from the developer's perspective
through visibly defined roles.
Blind coverage, since the tester
cannot target specific code segments
or error prone areas.
Large numbers of moderately skilled
testers can test the application with
no knowledge of implementation,
programming language, or operating
systems.
The test cases are difficult to design.

42. What Is The Purpose Of Black Box Testing?
Black box testing focuses on testing the complete
functionality of the system as well as its behavior.
This testing method is also referred to as behavioral testing
and functional testing.
This testing method is critical during the stages
of software testing life cycle like regression testing, acceptance,
unit, system, integration and software development.
The techniques of Black box testing are beneficial for the
end users who wish to perform software verification.

43. Techniques of Black Box Testing
.
BVA or Boundary Value Analysis:
It is one among the useful and critical Black box testing technique that
helps in equivalence partitioning. BVA helps in testing any software
having a boundary or extreme values

44. Advantages of Boundary Value Analysis
It is easier and faster to find defects using this technique. This is because the
density of defects at boundaries is more.
Instead of testing will all set of test data, we only pick the one at the
boundaries. So, the overall test execution time reduces.
Disadvantages of boundary value analysis
The success of the testing using this technique depends on the equivalence
classes identified, which further depends on the expertise of the tester and
his knowledge of the application. Hence, incorrect identification of
equivalence classes leads to incorrect boundary value testing.
Applications with open boundaries or applications not having one-
dimensional boundaries are not suitable for this technique. In those cases,
other black-box techniques like “Domain Analysis” are used.

45. This technique is capable of identifying the flaws of the limits
of the input values rather than focusing on the range of input
value. Boundary Value Analysis also deals with edge or extreme
output values.
Graph-Based Testing:

46. This technique of Black box testing involves a graph
drawing that depicts the link between the causes (inputs) and
the effects (output), which trigger the effects.
This testing utilizes different combinations of output and
inputs. It is a helpful technique to understand the software’s
functional performance, as it visualizes the flow of inputs and
outputs in a lively fashion.
Error Guessing Technique:
This testing technique is capable of guessing the erroneous
output and inputs to help the tester fix it easily. It is solely
based on judgment and perception of the earlier end user
experience.

47. Equivalence Class Partitioning:

48. This technique of Black box testing is widely used to write test
cases.
It can be useful in reducing a broad set of possible inputs to
smaller but effective ones.
It is performed through the division of inputs as classes, and
each class is given a value.
It is applied when the need for exhaustive testing arises and for
resisting the redundancy of inputs.

49. Advantages disadvantages
It is process-oriented All necessary inputs may not
cover.
We can achieve the Minimum test
coverage
This technique will not consider
the condition for boundary value
analysis.
It helps to decrease the general
test execution time and also
reduce the set of test data.
The test engineer might assume
that the output for all data set is
right, which leads to the problem
during the testing process.

50. Grey-Box Testing
Grey-box testing is a technique to test the application
with having a limited knowledge of the internal workings of an
application.
Grey Box Testing or Gray box testing is a software testing
technique to test a software product or application with partial
knowledge of internal structure of the application. The purpose
of grey box testing is to search and identify the defects due to
improper code structure or improper use of applications.
Gray Box Testing is a software testing method, which is a
combination of both White Box Testing and Black Box Testing
method.

52. Objective of Gray Box Testing:
1. The objective of Gray Box Testing is.
1. To provide combined advantages of both black box testing
and white box testing.
2. To combine the input of developers as well as testers.
3. To improve overall product quality.
4. To reduce the overhead of long process of functional and
non-functional testings.
5. To provide enough free time to developers to fix defects.
To test from the user point of view rather than a designer point
of view.

53. Types of Grey Box Testing
1. Matrix Testing:
In matrix testing technique, business and technical risks which are
defined by the developers in software programs are examined.
Developers define all the variables that exist in the program. Each
of the variables has an inherent technical and business risk and can
be used with varied frequencies during its life cycle.
2. Pattern Testing:
To perform the testing, previous defects are analyzed. It
determines the cause of the failure by looking into the code.
Analysis template includes reasons for the defect. This helps test
cases designed as they are proactive in finding other failures
before hitting production.

54. 3. Orthogonal Array Testing:
It is mainly a black box testing technique. In orthogonal array
testing, test data have n numbers of permutations and
combinations. Orthogonal array testing is preferred when
maximum coverage is required when there are very few test
cases and test data is large. This is very helpful in testing complex
applications.
4. Regression Testing:
Regression testing is testing the software after every change in
the software to make sure that the changes or the new
functionalities are not affecting the existing functioning of the
system. Regression testing is also carried out to ensure that fixing
any defect has not affected other functionality of the software.

55. Advantages of Gray Box Testing:
1. Users and developers have clear goals while doing testing.
Gray box testing is mostly done by the user perspective.
2. Testers are not required to have high programming skills for
this testing.
3. Gray box testing is non-intrusive.Overall quality of the product
is improved.
4. In gray box testing, developers have more time for defect
fixing.
5 . By doing gray box testing, benefits of both black box and
white box testing is obtained.
6. Gray box testing is unbiased. It avoids conflicts between a
tester and a developer.
7. Gray box testing is much more effective in integration testing.

56. Disadvantages of gray box testing:
1. Defect association is difficult when gray testing is
performed for distributed systems.
2. Limited access to internal structure leads to limited access
for code path traversal.
3. Because source code cannot be accessed, doing complete
white box testing is not possible.
4. Gray box testing is not suitable for algorithm testing.
5. Most of the test cases are difficult to design.