SOFTWARE TESTING (III-CS_ANITHA P)
UNIT-I
Software Development Life Cycle models: Phases of Software project –
Quality, Quality Assurance, Quality control – Testing, Verification and
Validation – Process Model to represent Different Phases - Life Cycle models.
White-Box Testing: Static Testing – Structural Testing –Challenges in White-
Box Testing.
INTRODUCTION AND FUNDAMENTALS
●WHAT IS SOFTWARE TESTING?
●WHY DO SOFTWARE TESTING?
●WHAT DO WE TEST?
●WHO DOES THE TESTING ?
WHAT IS SOFTWARE TESTING?
Software testing is a process of verifying and validating that a software application or
program.
“Testing is the process of executing a program with the intention of finding errors.”
OBJECTIVES OF TESTING:
To check if the system meets the requirements and be executed successfully in the
Intended environment. To check if the system is “Fit for purpose”. To check if the system
does what it is expected to do.
Motivation
People are not perfect. We make errors in design and code.
Goal of testing
How to test the software at various levels, given some code, uncover as many errors
are possible
Objective of a Software Tester
●Find bugs as early as possible and make sure they get fixed.
●To understand the application well.
●Study the functionality in detail to find where the bugs are likely to occur.
●Study the code to ensure that each and every line of code is tested.
●Create test cases in such a way that testing is done to uncover the hidden bugs
and also ensure that the software is usable and reliable.
VERIFICATION AND VALIDATION
Verification - typically involves reviews and meeting to evaluate documents, plans,
code, requirements, and specifications. This can be done with checklists, issues lists,
walkthroughs, and inspection meeting.
Validation - typically involves actual testing and takes place after verifications are
completed. Validation and Verification process continue in a cycle till the software
becomes defects free.
WHY DO SOFTWARE TESTING? SOFTWARE TESTING (III-CS_ANITHA P)
A “bug” is really a problem in the code; software testing is focused on finding defects
in the final product. Here are some important defects that better testing would have found.
●In February 2003 the U.S. TreasSury Department mailed 50,000 Social Security checks
without a beneficiary name. A spokesperson said that the missing names were due to a
software program maintenance error.
●In July 2001 a “serious flaw” was found in off-the-shelf software that had long been used
in systems for tracking U.S. nuclear materials. The software had recently been donated to
another country and scientists in that country discovered the problem and told U.S.
officials about it.
●In October 1999 the $125 million NASA Mars Climate Orbiter—an interplanetary
weather satellite—was lost in space due to a data conversion error. Investigators
discovered that software on the spacecraft performed certain calculations in English units
(yards) when it should have used metric units (meters).
●In June 1996 the first flight of the European Space Agency's Ariane 5 rocket failed shortly
after launching, resulting in an uninsured loss of $500,000,000. The disaster was traced to
the lack of exception handling for a floating-point error when a 64-bit integer was
converted to a 16-bit signed integer.
WHAT DO WE TEST?
A comprehensive testing regime examines all components associated with the
application.
Testing can involve some or all of the following factors. The more, the better.
●Business requirements
●Functional design requirements
●Technical design requirements
●Regulatory requirements
●Programmer code
●Systems administration standards and restrictions
●Corporate standards
●Professional or trade association best practices
●Hardware configuration
●Cultural issues and language differences
WHO DOES THE TESTING?
Software testing is not a one person job. It takes a team, but the team may be larger or
smaller depending on the size and complexity of the application being tested. The
programmer(s) who wrote the application should have a reduced role in the testing if
possible.
SOFTWARE DEVELOPMENT LIFE CYCLE (SDLC):
Phases of software project
A software project is made up of series of 6 phases,
1.Requirements gathering and Analysis
2.Planning
3.Design
4.Development or coding SOFTWARE TESTING (III-CS_ANITHA P)
5.Testing
6.Deployment and maintenance
1.Requirements gathering and Analysis
●During requirements gathering, the specific requirements of the software to be
built are gathered and documented.
●The right requirements are captured at every stage.
●The requirements get documented in the form of System Requirements
Specification (SRS) document.
UNIT-I
Software Development Life Cycle models: Phases of Software project –
Quality, Quality Assurance, Quality control – Testing, Verification and
Validation – Process Model to represent Different Phases - Life Cycle models.
White-Box Testing: Static Testing – Structural Testing –Challenges in White-
Box Testing.
INTRODUCTION AND FUNDAMENTALS
●WHAT IS SOFTWARE TESTING?
●WHY DO SOFTWARE TESTING?
●WHAT DO WE TEST?
●WHO DOES THE TESTING ?
WHAT IS SOFTWARE TESTING?
Software testing is a process of verifying and validating that a software application or
program.
“Testing is the process of executing a program with the intention of finding errors.”
OBJECTIVES OF TESTING:
To check if the system meets the requirements and be executed successfully in the
Intended environment. To check if the system is “Fit for purpose”. To check if the system
does what it is expected to do.
Motivation
People are not perfect. We make errors in design and code.
Goal of testing
How to test the software at various levels, given some code, uncover as many errors
are possible
Objective of a Software Tester
●Find bugs as early as possible and make sure they get fixed.
●To understand the application well.
●Study the functionality in detail to find where the bugs are likely to occur.
●Study the code to ensure that each and every line of code is tested.
●Create test cases in such a way that testing is done to uncover the hidden bugs
and also ensure that the software is usable and reliable.
VERIFICATION AND VALIDATION
Verification - typically involves reviews and meeting to evaluate documents, plans,
code, requirements, and specifications. This can be done with checklists, issues lists,
walkthroughs, and inspection meeting.
Validation - typically involves actual testing and takes place after verifications are
completed. Validation and Verification process continue in a cycle till the software
becomes defects free.
WHY DO SOFTWARE TESTING? SOFTWARE TESTING (III-CS_ANITHA P)
A “bug” is really a problem in the code; software testing is focused on finding defects
in the final product. Here are some important defects that better testing would have found.
●In February 2003 the U.S. TreasSury Department mailed 50,000 Social Security checks
without a beneficiary name. A spokesperson said that the missing names were due to a
software program maintenance error.
●In July 2001 a “serious flaw” was found in off-the-shelf software that had long been used
in systems for tracking U.S. nuclear materials. The software had recently been donated to
another country and scientists in that country discovered the problem and told U.S.
officials about it.
●In October 1999 the $125 million NASA Mars Climate Orbiter—an interplanetary
weather satellite—was lost in space due to a data conversion error. Investigators
discovered that software on the spacecraft performed certain calculations in English units
(yards) when it should have used metric units (meters).
●In June 1996 the first flight of the European Space Agency's Ariane 5 rocket failed shortly
after launching, resulting in an uninsured loss of $500,000,000. The disaster was traced to
the lack of exception handling for a floating-point error when a 64-bit integer was
converted to a 16-bit signed integer.
WHAT DO WE TEST?
A comprehensive testing regime examines all components associated with the
application.
Testing can involve some or all of the following factors. The more, the better.
●Business requirements
●Functional design requirements
●Technical design requirements
●Regulatory requirements
●Programmer code
●Systems administration standards and restrictions
●Corporate standards
●Professional or trade association best practices
●Hardware configuration
●Cultural issues and language differences
WHO DOES THE TESTING?
Software testing is not a one person job. It takes a team, but the team may be larger or
smaller depending on the size and complexity of the application being tested. The
programmer(s) who wrote the application should have a reduced role in the testing if
possible.
SOFTWARE DEVELOPMENT LIFE CYCLE (SDLC):
Phases of software project
A software project is made up of series of 6 phases,
1.Requirements gathering and Analysis
2.Planning
3.Design
4.Development or coding SOFTWARE TESTING (III-CS_ANITHA P)
5.Testing
6.Deployment and maintenance
1.Requirements gathering and Analysis
●During requirements gathering, the specific requirements of the software to be
built are gathered and documented.
●The right requirements are captured at every stage.
●The requirements get documented in the form of System Requirements
Specification (SRS) document.
