Integration Testing
Presented By
Nesreen Ahmad
*Main Points: Definition
Of Integration Testing.
 Procedure Of Integration Testing.
 Integration Testing Strategies.
Definition Of Integrated Testing

Detects faults that have not been
detected during unit testing by focusing
on small groups of components .
Procedure Of Integration Testing

Two or more components are integrated and
tested, and when no new faults are revealed
(discovered), additional components are
added to the group.

This procedure allows the testing of
increasingly more complex parts of the
system while keeping the location of potential
faults relatively small.
Integration Testing Strategies

Big Bang Testing.
 Bottom-Up Testing.
 Top-Down Testing.
 Sandwich Testing.
Layer I
User Interface (A)
Layer I I
Billing (B)
Event Service (C)
Learning (D)
Layer III
Database (E)
Network (F)
Neural Network (G)
First: Big Bang Testing

This strategy assumes that all components
are first tested individually and then tested
together as single system.

Advantage: That no additionally test stubs or
drivers are needed.

Disadvantage:
1- It is expensive.
2- It is difficult to pinpoint the specific
components (or combination of components).
Second: Bottom-Up Testing
 Strategy
first tests each component of
the bottom layer individually, and then
integrates them with components of the
next layer up.
User Interface (A)
Billing (B)
Event Service (C)
Learning (D)
Neural Network (G)
Database (E)
Network (F)
- Bottom-Up test strategy -
 Advantage:
Interface faults can be more
easily found.
 Disadvantage:
Faults found in the top
layer may often lead to change in the
subsystem decomposition or in the
subsystem interfaces of lower layers.
Third: Top-Down Testing
 Tests
the components of the top layer
first, and then integrates the
components of the next layer down.
When all components of the new layer
have been tested together, the next
layer is selected.
User Interface (A)
Billing (B)
Event Service (C)
Learning (D)
Neural Network (G)
Database (E)
Network (F)
- Top-Down test strategy -
 Advantage:
It starts with user interface
components.
 Disadvantage:
1-The development of test stub is
time-consuming and prone error.
2- A large number of stubs is usually
required for testing nontrivial systems.
Fourth: Sandwich Testing
 Combines
the top-down and bottom-up
strategies, attempting to make use of
the best of both.
 There
are Three Layers:1-Target Layer (“the meat”).
2-The Layer above the target layer.
3-The Layer below the target layer.
Top Layer
Test A
Test A, B
Test A, C
Test A,B,C,D
Test A, D
Bottom Layer
Test D,G
Test G
Test F
Test B,E,F
Test E
Test A,B,C,D,E,F,G
- Sandwich Testing Strategy -
Top Layer
Test A
Target Layer
Test A, B
Test A, C
Test A,B,C,D
Test A, D
Test B
Test C
Test D
Bottom Layer
Test D,G
Test G
Test F
Test E
Test B,E,F
Test A,B,C,D,E,F,G
- Modified Sandwich Testing Strategy -

The advantage of modified sandwich
testing: Many testing activities can be
performed in parallel.

The disadvantage of modified sandwich
testing: Is needed for additional test stubs
and drivers.