Transcript Introduction to Software Testing v1.0

Introduction to Software Testing
Module Objectives
• Introduction to Software Testing
• Importance of Software Testing
• Verification and Validation
• Software Test Lifecycle
• Testing Process
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Goal of testing
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The goal of a software tester is:
To find bugs
To find them as early as possible
& make sure they get fixed
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Testing is a means to:
Find bugs
Provide confidence and information
Even prevent defects
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Why is testing needed
 A defect in the software has a root cause, while the effect of defect is
seen as impact by the different stake holders.
 Testing is part of overall Quality Assurance – It covers the Quality
Control aspect of ensuring Quality
 A fault doesn't necessarily result in a failure, but a failure can only occur if a
fault exists. To avoid a failure you must find the fault.
 Software testing may be required for compliance with contractual or legal requirements
 When is testing complete?
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Actually never
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However for practical reasons it is stopped after considering the
risks involved, time and budget constraints
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Why is testing needed
Why is testing needed
 Complexity of software makes it error prone
 Untested or weakly tested software can cause losses in real life. Eg:
• Disney’s Lion King – 1994 – 1995- The software did not work on
the most common systems that the public had.
• Intel Pentium Floating-Point Division Bug – 1994 – Intel took a
charge of more than $400 million to cover the costs of replacing
bad chips
• NASA Mars Polar Lander – 1999 – Malfunction due to an
unexpected setting of a single data bit
• Patriot missile defense system – 1991 – A software bug caused
the tracking system to be inaccurate after 14 hrs of operation
 Software bugs can cause harm to a person, to the environment or to a
company
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Testing Profession
Who makes a Good tester
The tester’s mindset must have the below mentioned attributes
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Keen Observation
Questioning Skills
“Never give-up” attitude
Interpersonal Skills
The V-Model
The V-model can be said to have
developed as a result of the evolution of
software testing. Various testing
techniques were defined and various kinds
of testing were clearly separated from
each other which led to the waterfall model
evolving into the V-model. The tests in the
ascending (Validation) hand are derived
directly from their design or requirements
counterparts in the descending
(Verification) hand. The ‘V’ can also stand
for the terms Verification and Validation.
SDLC and STLC
The Testing Process
Project Initiation
Test Strategy and Planning
Test Environment setup
Test Case Designing
Test Execution
Test Cycles
Defect Reporting and Tracking
Project closure
References
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http://knol.google.com/k/istqb-certification-answers-of-all-tests-chapter-1-6#
http://9th-direction.com/ISTQB/ISTQB-Question-Paper-Dump-6.pdf
http://istqb.org/download/attachments/2326555/Foundation%20Level%20Syllabus
%20(2010).pdf
http://istqb.patshala.com/
Thank you