Session 1 Software Testing an Introduction V1

8/2/2019 Session 1 Software Testing an Introduction V1

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2007, Cognizant Technology Solutions. All Rights Reserved.The information contained herein is subject to change without notice. C3: ProtectedC3: Protected

Fundamentals of

Software Testing

Session 1: Software TestingAnIntroduction


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About the Author

Created By: Vijayan Kanagaraj (223562) ; Ramesh Kumar, Moses

(125587)CredentialInformation:

Vijayan holds a B.Tech degree and has 8 years ofExperience in Software Testing

Moses has an MCA degree and has 11 years ofExperience in Software Testing

Version and

Date:

ST/PPT/2010/1.0

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Icons Used

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Questions

Contacts

Reference

Try it Out

Hands-onExercise

CodingStandards

Test YourUnderstanding

Tools

AWelcomeBreak


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Software TestingAn Introduction:Overview

Introduction: This session gives an overview on Software Quality

and Software Testing. It helps the audience

understand the necessity and the key aspects of

Software Testing.


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Software TestingAn Introduction:Objectives

After completing this session, you will be ableto:

Define Software Quality

List the Software Quality Attributes

Describe Verification and Validation

Define Software Testing

Recognize the significance of Software Testing

Recognize how testing improves Software Quality

Discuss the history and evolution of Software Testing

Describe Software Testing Principles Define Software Defect

Recognize the significance of Software Defect

Describe the Software Testing Model

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Software Quality measures how well the software is designed

(quality of design), and how well it conforms to that design

(quality of conformance).

Two Dimensions of Software Quality are:

Producers view (by Phil Crosby) Meeting therequirements specification

Consumers view (by Deming & Juran) Fit for use

The major premise of Software quality is to focus on continuous

improvement best illustrated by the Demings wheel or the

PDCA cycle.

Software Quality


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Software Quality attribute is a property of a software product that are

and should bequantifiable in specifications by appropriate and

practical scales of measure.

The ISO software-quality model [ISO 2001] defines six quality-

attribute categories:

Functionality Meeting the requirements

Reliability Trustworthiness of the Software

Usability User friendliness

Efficiency Amount of computing resources and code required by a

program to perform a function

Maintainability How easy it is to modify the existing code and reuse for

future changes

Portability How easy it is for the software to adapt itself to various

operating environments

Software Quality Attributes


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Key Processes to Improve SoftwareQuality

Verification:

Process of confirming that anysoftware developmentconforms to its standards andmeets the specification

Refers to the review process,which includes reviews,inspections and Walk through

Helps to verify if the applicationis built to meet therequirement/design

specifications - Are we buildingthe product right?

Process of reviewing the designdocuments created during eachphase and linked to Testingactivities like creation of TestPlan, Test Design

Validation:

Process of confirming thatevery software meets theuser's requirements

Validation is the TestingProcess and it includes fewtechniques like Black BoxTesting & White Box Testing

Helps to validate if theapplication will meet userneeds - Are we building the

right product?

Process of executing the Testsat the various levels

Both Functional and Nonfunctional requirements aretested using Validation

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Verification and Validation are key Processes to improve SoftwareQuality.


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Verification Vs. Validation

Verification Validation

This process focuses upon theprocess of developing and testing asoftware in an Organization.

This process focuses on the productafter the development phase orduring the development

Verification begins in the initialphase and will be always associated

with all the phases of SDLC

Validation appears after codingphase

Primarily, Quality Assurance (QA )engineers will be involved in theprocess of verification

Primarily, test engineers will beinvolved in the phase of validation.

Are we building the Product Right? Are we building Right Product?

Testing is a validation process to improve the quality of the software.


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Computer System Failures Causedby Software Defects

Reliability and performance of Software systems is of crucial

importance for the effective and efficient management of oursocial systems, be it business or otherwise.

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Photo of what is possibly thefirst real bug found in acomputer.

Two adjacent roads both get thegreen light at this T-intersection.This is a classic example of aSoftware failure which mightresult in loss of life.


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What is Software Testing

Introduction: Software Testing is an activity that helps inidentifying bugs/defects/errors in a software systemunder development, in order to provide a defect-freeand reliable system/solution to the customer.

Software Testing is the process of questioning aproduct in order to evaluate it, where the"questions" are things the tester tries to do with theproduct, and the product answers with its behaviorin reaction to the probing of the tester.

Software Testing helps to identify the correctness,completeness, and quality of developed computersoftware.

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Why is Software Testing Necessary?

Significance of Software Testing:

To produce a quality product, which is defect free. To make sure all the requirements are satisfied and

the best design system architecture is used.

To ensure Customers/user satisfaction.

To reduce the possible risks associated with the

software, thereby reducing the loss.

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A clever person solves a problem. A wise personavoids it.- Albert Einstein


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How Testing Improves the SoftwareQuality

Testing helps to measure the quality of software interms of the number of defects found, the tests run,and the system requirements covered by the tests.

Testing helps to find defects and the quality of thesoftware increases when those defects are fixed therebyreducing the overall level of risk in a system.

Testing helps to improve the quality by ensuring theproduct:

meets the user requirements

meets the conformance standards & Guidelines,

meets the performance standards

provides stability to the system

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How Testing Improves SoftwareQuality (Contd.)

What is a Software Defect? Software Defect can be defined as nonconformance to

requirements or functional specification.

Software defect is a common term used to describe error, fault,

failure, bug, defect, etc.

Software defects are classified based on severity and priority.

Common reasons for a defect in a software:

Misinterpretation/Misunderstanding of Business Requirements

Changing requirements Software Complexity

Poor Design/Coding logic

Human errors

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Significance and Cost of SoftwareDefect

The presence of defects in a

Software system has anegative impact on thequality of the Software andshows the deviations in thedesign practice andprinciples.

The cost of defect is directlyimpacted by when thosedefects are found.

The cost of finding andfixing defects rises

considerably across the lifecycle.

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History and Evolution of SoftwareTesting

Software has been tested as

early as software has beenwritten. The concept oftesting itself evolved withtime.

Debugging oriented

Demonstration oriented Destruction oriented

Evaluation oriented

Prevention oriented

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Basics of Software Testing

What to test?

To test that the Product has been developedaccording to specification

To test that the functionality is working well

To test that the product satisfies user requirements

How to test? Manually

Using tools

Both manually and by using tools

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Basics of Software Testing (Contd.)

When to stop testing?

Critical or Key Test cases successfully completed.Certain test cases, even if they fail, may not be showstoppers.

Testing budget of the project or when the cost of

continued testing, does not justify the project cost. Functional coverage, code coverage, meeting the

client requirements as per the target benchmark.

Defect detection rates fall below certain specifiedlevel & High priority bugs are resolved.

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General Testing Principles

A number of testing principles have beensuggested over the past 40 years and offergeneral guidelines common for all testing.

Principle 1 Testing shows presence of defects

Principle 2 Exhaustive Testing is impossible

Principle 3 Testing can start as early in theSDLC

Principle 4 Defect clustering

Principle 5 Same Tests repeated over a period oftime reduces Test Effectiveness

Principle 6 Testing is context dependant

Principle 7 Absence-of-errors fallacy

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Alignment of Testing Model to VariousDevelopment Methodologies

Various generic software development life cyclemethodologies are available for executingsoftware development projects.

Each process model follows a particular lifecycle in order to ensure success in process ofsoftware development.

Basic popular methodologies that are adoptedfor software development:

Waterfall

Iterative

Spiral

Agile

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Testing Process for A WaterfallDevelopment Methodology

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RequirementsStudy &Analysis

Design, Code,& Unit Test

TestingSystemTesting

ComponentIntegration

Testing

TestDesign

TestRequirementAnalysis &

Test Planning

SDLC STLC

SystemIntegration

Testing

d l d l f f ll


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V ModelTesting Model for WaterfallMethodology

The V-Model is the Testing model adopted while the

development methodology is Waterfall. Instead of goingdown in a linear way the process steps are bentdownwards to UAT, to form the typical V -Shape.

V-model illustrates how testing activities (Verificationand Validation) can be integrated into each phase of thesoftware development life cycle.

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T i P i A il D l


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Testing Process in Agile Development(Contd.)

Agile Development Testing Process

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Feature ADesign Develop Test

Rework

Feature BDesign Develop Test

Rework

Feature CDesign Develop Test

Rework

Feature DDesign Develop Test

Rework

Feature EDesign Develop Test

Rework

Cross-Functional Team (Designers, Developers, Testers)


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Allow time for questions from participants

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Test Your Understanding

1. What is the primary objective of testing?

A. To show that the program works

B. To provide a detailed indication of quality

C. To find errors

D. To protect the enduser

2. Pick the best option for quality

A. Quality is job done

B. Zero defects

C. Conformance to requirements

D. Work as designed

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S ft T ti A I t d ti


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Software TestingAn Introduction:Summary

Heres a brief recap of this session:

Each Software has various quality attributes.

The quality of a software program can be improvedusing Verification and Validation processes.

Verification refers to reviews, checklist, and similar

process related activities. Validation is primarily testing of a developed

software against the requirements specifications.

Validation helps in identifying whether the rightproduct is built based on the specification.

Software Testing is an activity that helps in locatingbugs/defects/errors in a software system.

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Software TestingAn Introduction:Summary (Contd.)

Software defect is a common term used to describe

error, fault, failure, bug, defect, etc. and there aredifferent stages of software defect life cycle.

Software testing reduces the likelihood of failure andensures that the probability of the Software meetingthe standards specified by the user is high.

Complete testing is not possible for almost allprojects and a determination needs to be made earlyon when to stop testing.

The V-Model demonstrates the relationships betweeneach phase of the development life cycle and itsassociated phase of testing.

The testing methodology may vary depending on thedevelopment methodology.

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Software TestingAn Introduction:Source

Reference Websites:

www.onestoptesting.com

www2.sas.com

www.softwaretestinggenius.com

http://en.wikipedia.org/wiki/Software_bug

Reference Books: Software Testing FundamentalsConcepts, Roles, and

Terminology by John E. Bentley, Wachovia Bank, CharlotteNC

Basics of Software Testing by Divya Saxena

ISTQB

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Disclaimer: Parts of the content of this course is based on the materials available from the Websites and

books listed above. The materials that can be accessed from linked sites are not maintained by Cognizant

Academy and we are not responsible for the contents thereof. All trademarks, service marks, and trade

names in this course are the marks of the respective owner(s).
http://www.onestoptesting.com/http://www.onestoptesting.com/http://www.softwaretestinggenius.com/http://en.wikipedia.org/wiki/Software_bughttp://en.wikipedia.org/wiki/Software_bughttp://en.wikipedia.org/wiki/Software_bughttp://www.softwaretestinggenius.com/http://www.onestoptesting.com/http://www.onestoptesting.com/


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2007, Cognizant Technology Solutions. All Rights Reserved.The information contained herein is subject to change without notice.

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Session 1 Software Testing an Introduction V1