2. Overview
Abstract
Problem Definition
◦ Need for Software Testing?
◦ Infamous Error Case studies
◦ Software Bug and its Effects
Literature Survey
Black-Box Testing
White-Box Testing
Static Testing & Dynamic Testing
Applying the testing methods
Design for Implementation
Conclusions
3. ABSTRACT
Here, main testing methods and
techniques are shortly described
General Classification is outlined: two
Testing methods-“Black-Box” and
“White-Box” Testing & their frequently
used techniques
4. PROBLEM DEFINITION
Need for Testing software:
• Software is everywhere. However it is
written by people- hence it’s not perfect.
Infamous software errors:
• 1.Disney’s Lion king:- failed as disney didn’t
test the game on different PC platforms.
• II.Intel Pentium Floating Point Division Bug:-
(4135835/3145727)*3145727-4135835
• The answer is zero, but old Intel CPU
didn’t give the right answer.
5. Problem Definition Contd.. (Software Bug and its
Effects)
Any software failure
is called as a Bug
Other terms used:
i. Defect
ii. Variance
iii. Fault
iv. Failure
v. Problem
vi. Inconsistency
vii. Error
viii. Feature
ix. Incident
x. Anomaly
Cost of Bugs
The Costs are logarithmic-
they increase by tenfold as
the time increases
6. Literature Survey
Goal of software tester[1]
“The goal if the software tester is to find bugs,
find them early, and make sure they are fixed as
soon as possible”
Software Testing Fundamentals[1]
Testing the Specification.
Testing the Software with Blinders On
Examining the Code.
Testing the Software with X-Ray Glasses.
7. BLACK-BOX TESTING[5]
Here tester knows only
what the software is
supposed to do(he
can’t look in the box to
see how it operates
No access to software
code
He a input, he
gets a certain output
but doesn’t how or
why it happens, just
that it does.
8. WHITE-BOX TESTING[5]
Also called as clear
box testing
Tester can see
inside the box ie.,
has access to
program’s code
9. STATIC & DYNAMIC TESTING[1]
• Refers testing to
something which is not
running-examining and
reviewing it.
STATIC
TESTING:-
• testing the software by
running it(normally what
we think of as testing).
DYNAMIC
TESTING:-
10. TESTING THE
SPECIFICATION[1]
Also called Static Black-Box Testing.
How is it Done??
Stati
c
BlackBo
x
• Pretend to be the Customer.
• Research Existing Standards & Guidelines.
• Review & Test Similar Software.
High level
Review
• Specification Attribute Checklist.
• Specification Terminology Checklist
Low level
Review
Attribute CheckList
1. Complete 2. Accurate 3. Precise, Unambigous, Clear
4. Consistent 5. Relevant 6. Feasible
Terminology CheckList
1. Always, Every, All, None, Never
2. Certainly, Therefore, Clearly
3. Some, Sometimes, Often, Usually,Etc., And So Forth, And So On,
Such As
4. 5.If…Then…(missing Else)
11. TESTING THE SOFTWARE
WITH BLINDERS ON[1]
Also called as Dynamic Black-Box
Testing.
How is it Done??
Dynami
c
BlackBo
x
Data Testing:
1) Boundary Conditions:
2) Sub-Boundary Conditions:- (refers to internal boundaries)
3) Default, Empty, Blank, Zero or None.
4) Invalid, Incorrect, Wrong, Garbage.
State Testing:
Testing s/w logic flow(by creating state transition map).
int data[]=new int[5];
for(int i=1;i<5;i++)
data[i]=-1;
data[1]=-1
data[2]=-1
data[3]=-1 what about
data[0]???
data[4]=-1
12. EXAMINING THE CODE[1]
Also called Static White Box testing
How is it Done??
What is to be done??
1. Formal
Reviews.
2. Peer Reviews.
3. WalkThroughs
4. Inspections.Coding Standards and Guidelines
Generic Code Review Checklist
Stati
c
Whitebox
13. TESTING THE SOFTWARE
WITH XRAY GLASSES[1]
Also called as Dynamic White-Box
Testing
How is it Done??
Code Coverage
14. ◦ Statement Coverage
◦ Branch Coverage
◦ Condition Coverage
If Date=01-01-2000
Lines 1,2,3,4,5,6,7
If Date<>01-01-2000
Lines 1,2,5,6,7
Code Coverage
1. PRINT “Hello World”
2. IF Date$ = “01-01-2000”
THEN
3. PRINT “Happy New Year”
4. END IF
5. PRINT “The date is: “; Date$
6. PRINT “The time is: “; Time$
7. END
◦ Consider the following code
1. PRINT “Hello World”
2. IF Date$ = “01-01-2000” AND Time$ = “00:00:00”
THEN
3. PRINT “Happy New Year”
4. END IF
5. PRINT “The date is: “; Date$
6. PRINT “The time is: “; Time$
7. END
Date=01-01-0000
& Time=11:11:11
• Lines 1,2,5,6,7
Date=01-01-0000
& Time=00:00:00
:-
• Lines 1,2,5,6,7
Date=01-01-2000
& Time=11:11:11 :-
• Lines 1,2,5,6,7
Date=01-01-2000
& Time=00:00:00
• Lines
1,2,3,4,5,6,7
PRINT “Hello World”
Date=
01/01/2000
Time=
00:00:00
PRINT ”Happy New Year”
PRINT Date
PRINT Time
YES
YES
NO
NO
1
2
2
3
4
5
6
7
Condition 1 Condition 2
15. DFD Diagram
Check if
input is
proper
User
Sort the
input list
Enter a List of numbers
to be sorted
Return sorted list
Ask for re input
(improper)
Proper input
16. CONCLUSIONS
Software testing is a component of software
quality control (SQC).
If customers are dissatisfied with a product,
they will never recommend that product, so
product’s cost and its popularity at the market
will decrease.
Eventual bugs and defects reduce
application functionality, do not look
vocational, and disturb company’s reputation.
Hence, radically Testing is very important to
conduct.
At that way, the defects can be discovered
and repaired.
17. REFERENCES
1. Ron Patton “Software Testing”
2. http://www.his.sunderland.ac.uk/~cs0mel/comm83wk5
.doc, February 08, 2009.
3. Stacey, D. A., “Software Testing Techniques”
4. Guide to the Software Engineering Body of
Knowledge, Swebok – A project of the IEEE Computer
Society Professional Practices Committee, 2004.
5. “Software Engineering: A Practitioner’s Approach, 6/e;
Chapter 14: Software Testing Techniques”,
R.S.Pressman & Associates, Inc., 2005.
6. Myers, Glenford J., IBM Systems Research Institute,
Lecturer in Computer Science, Polytechnic Institute of
New York, “The Art of Software Testing”, Copyright
1979. by John Wiley & Sons, Inc.
