Software testing

• Software Development life cycle (SDLC)
• Definition of testing
• Principles of testing
• Testing technique & Types
• Software Testing life Cycle (STLC)
• Defect Life Cycle (DLC)
Agenda

SDLC
•Coherent sets of activities for specifying, designing, implementing and
testing software systems
•A structured set of activities required to develop a software system
SDLC

• Waterfall model
• Spiral model
• V model
• V & V model
• Agile Methodology
SDLC

Water fall model
The standard waterfall model also called as Life cycle model for
systems development and an approach that goes through the
following steps:
• Document system concept
• Identify system requirements and Analyze them
• Break the system into pieces (Architectural Design)
• Design each piece (Detailed Design)
• Code the system components and test them individually
(Coding, Debugging, and Unit Testing)
• Integrate the pieces and test the system (System Testing)
• Deploy the system and operate it
Note: This model is useful when all the requirements are clear for the
system development
SDLC-Waterfall

Requirements
Design
Code & Unit Test
Test & Integration
Operation & Maintenance
Requirements
Design
Code & Unit Test
Test & Integration
Operation & Maintenance
SDLC -Waterfall model

V & V Model
Tests
Tests
Business
Requirements
Tests
Tests
System
Specification
Tests
Design
Specification
Code
Integration Testing
in the Small
Integration Testing
in the Large
System
Testing
Component
Testing
Acceptance
Testing
Run
Tests
Design
Tests
Project
Specification

Agile Methodology
• “We are uncovering better ways of developing software by
doing it and helping
• others do it. Through this work we have come to value:
– Individuals and interactions over processes & tools
– Working software over comprehensive documentation
– Customer collaboration over contract negotiation
– Responding to change over following a plan
• That is, while there is value in the items on the right, we
value the items on the

Principles Of Agile Software
• Partner with Customers
• Work Toward a Shared Vision
• Deliver Incremental Value
• Working software is the primary measure of progress
• Requirements evolve
• Embrace change
• Sustainable development
• Invest in Quality and technical excellence
• Empower Team Members
• Interact with Business on a daily basis
• Establish Clear Accountability
• Learn from all experiences
• Foster open communications

Agile-Roles in Agile Project
• The Customer or Customer Proxy who is responsible for defining the
requirements, priorities and accepts delivery of the completed User Stories.
• The Project Manager who is responsible for delivering the completed
system to the Customer.
• The Business Analyst (who often acts as a Customer Proxy) is responsible
for ensuring that the requirements are fully formed into proper User Stories
with accompanying Acceptance Criteria.
• The Designer is responsible for ensuring a coherent technical design with
appropriate levels of quality, performance etc which satisfies the Customer's
requirements.
• The Developer is responsible for delivering software code which fulfils
User Stories by meeting their Acceptance Criteria.
• The Tester is responsible for ensuring that the Acceptance Criteria tests are
run and that they pass. In addition they are responsible for ensuring the
overall quality of the system.

Agile-Additional Roles
• The Agile Coach is an experienced Agile practitioner who is responsible for
helping the team adopt Agile Practices. The Agile Coach may also take on
the Iteration Manager role.
• The Agile Enablers who work within the team in specific roles. Agile
favors learning via interactions between individuals, teams benefit greatly if
they are seeded with experienced Agile Enablers in areas such as the
Developer, Business Analyst and Tester teams.
• The Build Master, usually a Developer who has specific experience and
skills in setting up and maintaining a Continuous Integration environment.
• The Iteration Manager who takes on the inward focusing parts of the
Project Manager role, specifically dealing with ensuring that the team is
productive and that the iterative process is running smoothly.
• The Technical Lead, usually a senior Developer working within the
Developer team, who is responsible for ensuring that the technical Common
Vision is maintained. The Technical Lead works closely with the Designer
in order to both communicate design goals to the team and to provide
feedback to the Designer about implementation issues.

Agile Process FlowRequirements & Planning Development Iteration (2-4 Weeks) Deployment
User
Stories
Estimation
Release
Planning
Iteration
Zero
Iteration
Planning
Iteration
Kick-off
Daily
Activities
Showcase
Iteration Demo
Iteration
Retrospective
Continuous
CAT
(UAT)
Production
Deployment
Continuous Integration
Automated Testing
TrackingDevelopment
Automated Builds
Automated Deployment
Daily Stand-ups
Iteration Tracking
Simple Design
Refactoring
Coding
Automated Unit Testing
Automated Functional Testing

• Testing
– The process of exercising software to verify that
it satisfies specified requirements and to detect
faults
– The purpose of testing is to show that a program performs its
intended functions correctly
– Testing is the process of executing a program with the
intent of finding errors
– Software testing validates the behavior of a program with a
finite set of test cases, against the specified expected
behavior
Testing Defined

Principles of Testing
 What do Software Faults cost
 What is a bug
 Error – Fault – Failure
 Reliability versus faults
 Why do faults occur in software?
 Why is testing necessary?
 Why not just test everything?(complete testing)
 The most important principle.

What do Software Faults cost?(Cost of Quality)
• Cost of quality is the term that is used to quantify the total cost of
failure, appraisal and prevention costs associated with the
production of software.
• The cost of quality will vary from one organization to the next.
• The goal is to optimize the production process to the extent that
rework is eliminated and inspection is built into the production
process.
• Apply the concepts of continuous testing to the systems
development process can reduce the cost of quality

What is a bug ?
Any deviation from requirements.
• Error: a human action that produces an incorrect result
• Fault: a manifestation of an error in software
– also known as a defect or bug
– if executed, a fault may cause a failure
• Failure: deviation of the software from its expected delivery or
service
• Software faults become software failures only when the exact
computation conditions are met, and the faulty portion of the
code is executed on the CPU
Failure is an event; fault is a state of
the software, caused by an error

A person makes
an error ...
… that creates a
fault in the
software ...
… that can cause
a failure
in operation
Error - Fault - Failure

Reliability versus faults
Reliability: the probability that software will not cause the
failure of the system for a specified time under specified
conditions
– Can a system be fault-free? (zero faults, right first time)
– Can a software system be reliable but still have faults?
– Is a “fault-free” software application always reliable?
.

Why do faults occur in software?
•Software is written by human beings
Who know something, but not everything
Who have skills, but aren‟t perfect
Who do make mistakes (errors)
•Under increasing pressure to deliver to strict deadlines
No time to check but assumptions may be wrong
Systems may be incomplete
•Incomplete and misunderstood system requirements, errors in
design and poor test coverage
•A good test case is one that has a high probability of finding an
as yet undiscovered error

So why is testing necessary?
•Because software is likely to have faults
•To learn about the reliability of the software
•To fill the time between delivery of the software and the
release date
•To prove that the software has no faults
•Because testing is included in the project plan
•Because failures can be very expensive
•To avoid being sued by customers
•To stay in business

Why not just "test everything"? (complete testing)
System has
20 screens
Average 4 menus
3 options / menu
Average: 10 fields / screen
2 types input / field
(date as Jan 3 or 3/1)
(number as integer or decimal)
Around 100 possible values
Total for 'exhaustive' testing:
20 x 4 x 3 x 10 x 2 x 100 = 480,000 tests
If 1 second per test, 8000 min, 133 hrs, 17.7 days
(not counting finger trouble, faults or retest)
10 secs = 34 wks, 1 min = 4 yrs, 10 min = 40 yrs
So, Exhaustive testing is not possible

The most important principle of testing
Prioritise tests
so that,
whenever you stop testing,
you have done the best testing
in the time available.

Testing technique
•A procedure for selecting or designing tests
•Based on a structural or functional model of the software
•Successful at finding faults
•„Best' practice
•A way of deriving good test cases
•A way of objectively measuring a test effort
Static Testing
Inspections, Walkthroughs and Reviews
The inspection process
Benefits of Inspection
Static Analysis
Dynamic Testing
Black Box Testing
White Box Testing
Using techniques makes testing
much more effective

Unit Test:
Unit testing verifies the smallest piece of a program (module) to
determine if the actual structure is correct and if the function the
code defines operates correctly and reliably(without crashing or
hanging)
Types of Testing- Unit testing

Testing types - Smoke testing
• Smoke Testing : Smoke testing( some times called as Sanity
test) is non-exhaustive software testing, ascertaining that the
most crucial functions of a program work, but not bothering
with finer details. The term comes to software testing from a
similarly basic type of hardware testing, in which the device
passed the test if it didn't catch fire the first time it was turned
on. A daily build and smoke test is among industry best
practices advocated by the IEEE (Institute of Electrical and
Electronics Engineers).
Who : Usually Done by the QA Team
When : Before actual testing.

System Test: As soon as an integrated set of modules has been
combined to form your application, system testing can then be
performed. System testing verifies the system-level reliability and
functionality of the product by testing your application in the
integrated system.
Note: QA team performs System testing/ done by independent test group
Integration Test: Integration testing is used to test the reliability
and functionality of groups of units (modules) that have been
combined together into larger segments. The most efficient method
of integration is to slowly and progressively combine the separate
modules into small segments rather than merging all the units into
large component.
Note: Test engineers performs Integration testing in development phase
Types of Testing- ST & SIT

Testing types- Regression Test
• Regression Test: Regression testing is the re-running of all
tests after a fix, change or enhancement has been made to the
code and a new build of the AUT has been delivered to QA.
Regression testing verifies that previously identified problems
have been fixed and changes to one part of your application
have not introduced new problems elsewhere. Changing a line
of code might cause a ripple effect that produces an unexpected
result in another part of your application. If you do not re-run
all of your test cases after your application has been
changed, you cannot be certain about the quality of the entire
system.
Who : Usually Done by the test engineers
When : After changes have been incorporated for the existing
functionality

Testing types- Adhoc testing
• Adhoc testing :Testing without a formal test plan or outside of
a test plan. With some projects this type of testing is carried
out as an adjunct to formal testing. If carried out by a skilled
tester, it can often find problems that are not caught in regular
testing. Sometimes, if testing occurs very late in the
development cycle, this will be the only kind of testing that
can be performed. Sometimes ad hoc testing is referred to as
exploratory testing.
Who : Usually Done by the skilled tester.
When :After normal testing .

Testing types- Compatibility test
• Compatibility Test: It checks how one product
works with another, efficiently share the same data
files simultaneously that resides in the same
computer‟s memory.
Who : Usually Done by the test engineer
When :In testing phase

Testing types - Usability testing
• Usability Testing:Usability is a quality attribute that
assesses how easy user interfaces are to use. The word
'usability testing' refers to testing done for improving
ease-of-use during the design process.
Who : Usually Done by the testers in users
prospective.
When : Before actual release

Testing types - Security Testing
• Security Test: How easy would it be for an unauthorized
user to gain access to this program. Testing of database and
network software in order to keep company data and
resources secure from mistaken/accidental users, hackers, and
other malevolent attackers.
Who : Usually Done by the network expert
When : Before actual release

System Test: As soon as an integrated set of modules has
been combined to form your application, system testing can
then be performed. System testing verifies the system-level
reliability and functionality of the product by testing your
application in the integrated system.
Note: QA team performs System testing/ done by independent
test group
Types of Testing

Acceptance Test: The objective of acceptance testing is to
verify if the application is fit for deployment. Acceptance testing
may include verifying whether the application is reliable, meets
the requirements for business, performs well, and has a consistent
look and feel.
Note: Acceptance testing is generally done by a QA person at
Client Location
Types of Testing - UAT

Performance testing :Testing with the intent of
determining how quickly a product handles a variety of events.
Automated test tools geared specifically to test and fine-tune
performance are used most often for this type of testing.
Load, Stress and Volume testing come under this testing.
When :Conducted so as to meet the Performance criteria
stated by the Client.
Who : By the performance test automation expert
Types of Testing- PT

Regression Test: Regression testing is the re-running of all
tests after a fix, change or enhancement has been made to the
code and a new build of the AUT has been delivered to QA.
Regression testing verifies that previously identified problems
have been fixed and changes to one part of your application have
not introduced new problems elsewhere. Changing a line of code
might cause a ripple effect that produces an unexpected result in
another part of your application. If you do not re-run all of your
test cases after your application has been changed, you cannot be
certain about the quality of the entire system.
Who : Usually Done by the test engineers
When :After changes have been incorporated for the existing
functionality
Types of Testing

•Plan Test
•Create Test Plan
•Design Test
•Design Test Cases
•Automate tests
•Create Test Automation Architecture
•Create Automated Test Scripts
•Execute Test
•Test Log
•Evaluate Test
•Test Report
STLC

Plan Test
Design Test
Automate tests
Evaluate Test
Execute Test
Automation
Yes
No
Yes
No Adherence To Exit Criteria
Software Testing life Cycle (STLC)

Test Lead Create Test Plan
QATP
Change
Request
DSRS
Project Approach
Entry Criteria:
•Project Kickoff Meeting
•DSRS should be
approved
Exit Criteria:
•Reviewed, Approved
and Base-lined QATP
Workflow Detail: Plan Test

Test Engineer Design test Cases
Architecture
Document
DSTD QATP Project Engineering
Guidelines
Change Request
QATC
Work Load
Analysis
Entry Criteria:
•Baselined
QATP, DSRS, DSTD
Exit Criteria:
•All the requirements are
mapped to Test cases to
meet the Test Objective
•Peer reviews comments
are tracked to closure
•Updated Traceability
matrix
Design Test workflow

Automate Test
Test Engineer
QATC
Test Lead Create Test Automation
Architecture
Test Automation
Architecture
Guidelines
Automated
Test Suite
Build
Test Script
QATP
Create Automated
Test Scripts
Test Automation
Architecture
Entry Criteria:
Exit Criteria:
Entry Criteria: Exit Criteria:

Automate Test
Test Engineer
QATC
Test Lead Create Test Automation
Architecture
Test Automation
Architecture
Guidelines
Automated
Test Suite
Build
Test Script
QATP
Create Automated
Test Scripts
Test Automation
Architecture
Entry Criteria:
•Signed off / baselined
test automation
architecture
•Frozen test suite
•Build has to be ready
Exit Criteria:
•Planned Test scripts are
developed
•Stability of script used
for automation is to be
checked
Entry Criteria:
•Identifying all test
cases that are to be
automated
•Validated Test
Scripts(if already
exists)
Exit Criteria:
•Test suite should cover all
the requirements
•Structure of the test suite
should be completed and
approved

Execute Test
Test Engineer Execute Test
QATCTest Suite Build
Test Log
Entry Criteria:
Exit Criteria:

Execute Test
Test Engineer Execute Test
QATCTest Suite Build
Test Log
Entry Criteria:
•Unit Testing completed by
engineering team
•Baselined QATP and QATC
•Software build ready for testing
•Test Data is available
Exit Criteria:
•Execution of Test Cases and
Test Scripts are complete
•Test Results captured

Evaluate Test
Test Lead Evaluate Test
QATCTest Suite Test Log
Test Log
Test
Report
QATP
Entry Criteria:
•System Testing Completed
•Results logged in Test log
•Test Log reviewed by
Peers/Lead
Exit Criteria:
•Test report generated and
distributed to stakeholders

Roles and Responsibility of For Software Test Process
Activity Artifact Owner Reviewer Approver
Create Test
Plan
QATP Test Lead Test Analyst,
PM, Test
Team
PM,Client.
Design Test
Cases
QATC Test
Engineer
Test Lead,
Test Team
Test Lead, PM,
Client.
Create Test
Automation
Architecture
Test
Automation
Architecture
Automated
Test Suite
Test Lead Test Analyst PM.

Roles and Responsibility of For Software Test Process
Activity Artifact Owner Reviewer Approver
Create
Automated
Test Scripts
Test
Scripts
Test
Engineer
Test Lead,
Test Team
Test Lead, PM,
Client.
Execute
Test
Test Log Test
Engineer
Test Lead,
Test Team
Test Lead, PM,
Client.
Evaluate
Test
Test
Report
Test Lead Test Analyst PM,Client.

• The tester has to first identify the defect.
• He has to characterize the defects based on the severity and
priority.
• Reports the bug to the development team.
• Once the bug is fixed by the developer, tester retests the
same test case for validation.
• Test the related test cases for any adverse effects.
Defect Life Cycle- (DLC)

Defect Life Cycle- (DLC)
New Open
In
Progress
Fixed
Verified
Fixed
Closed
Deferred
Cannot
Reproduce
Documented
Is
Duplicate
As
Designed

DLC-Reason for a defect
• Defects may occur because of the following reasons:
– Time pressure
– Code complexity
– Change in technologies
– Change in requirements
– Programming errors
– Miscommunication
– Wrong Interpretation
– Unavailability of software resources
– Lack of human resources

Software testing

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