Software Testing Knowledge Level: Basic. 2 ©Copyright 2004, Cognizant Academy, All Rights Reserved...

Software TestingSoftware TestingSoftware TestingSoftware Testing

Knowledge Level:Knowledge Level:

BasicBasic

©Copyright 2004, Cognizant Academy, All Rights Reserved 2

Courseware Metadata

Created By: Testing Services, Cognizant

Credential Information:

Testing Team

Version and Date:

1.0


Courseware Information

Course Description

This course is to learn about software testing, its importance,lifecycle,types and levels of testing,test artifacts,defect management,test automation,a sample automation tool, performance testing and TCP.

Prerequisites

Target Audience


Course Objective & Outline

Course Objective:After completing this course, you will be able to know about software testing, its evolution,

lifecycle, types and levels of testing, testing techniques,test plan, test strategy, test cases, functional and performance testing, defect management , about test automation, a sample test automation tool and about Test Case Point analysis.

Course Outline:1. Introduction to software testing

1. What is software testing?2. Testing lifecycle3. Testing techniques 4. Types of testing

2. Black box Vs White box testing1. Black box testing2. White box testing3. Black box Vs White box


Course Objective & Outline

Course Outline contd….3. Other testing types

1.GUI testing

2.Regression testing

3.Acceptance testing

4.Configuration testing and Installation testing

5.Alpha testing and Beta testing

4. Levels of testing

1.Unit testing

2. Integration testing

3. System testing


1.0 Introduction to Software Testing : Overview

Introduction:

In this module let’s see what is software testing ,its process and lifecycle, types of testing and techniques of testing.

Objective:

After completing this module, you will be able to know what is software testing, its evolution, lifecycle and testing techniques.


1.1What is Software testing?: Overview

Testing – What Is it ???

A process of demonstrating that errors are not present ?

OR

A way of establishing confidence that a program does what it is supposed to do ?

OR

A means of achieving an error-free program by finding all errors ?


1.1What is Software testing? Contd..

What is software testing?

The process of executing computer software in order to determine whether the results it produces are correct”, Glass ‘79“The process of executing a program with the intent of finding errors”, Myers ’79A “DESTRUCTIVE”, yet creative process

Testing is the measure of software quality”, Hetzel ‘85


1.1What is Software testing ?contd..

Why Testing? Verifies that all requirements are implemented correctly (both for

positive and negative conditions) Identifies defects before software deployment Helps improve quality and reliability. Makes software predictable in behavior. Reduces incompatibility and interoperability issues. Helps marketability and retention of customers.


Quality Control VS

Quality Assurance

Quality Control : Mechanism to ensure that the required quality characteristics exist in the finished product

Quality Assurance : Ensures that the quality management procedures work


Source of Defects

56%27%

7%10%

RequirementsDesign

CodeOther

Source: “Software Testing in the Real World”

- Edward Kit, 1995


1.2 Testing lifecycle

Development Lifecycle

Project Planning

Requirements Capture

Implementation

Build 0 Build 1 Build 2

Test Lifecycle

Plan Test

Analysis & Design

Design Test

Setup Test Bed

Execute Test

Evaluate Test

Defect Tracking/Enhancement Request


1.2 Testing lifecycle contd…

Requirements Capture

Analysis

Test planning & Scenario Design

Test Case Development

Test Execution

Test Result Analysis

Test Cycle Closure

Defect Fixing Cycle

Defects

New Version

The Scenarios Design and the Test Case Development could normally start in parallel with the Development Cycle.Test Execution Synchs up with the Development Cycle during the functional Testing Phases


Testing in the V Model Approach

Verification Validation

Requirements

(Business Needs)

Requirements

(Business Functions)

Design

Code

Acceptance Testing

System Testing

Integration Testing

Unit Testing

Write

testsRun

tests


Definitions

Bug/DefectDeviation from specification or standard

ValidationThe test phase of the life cycle which ensures that the end product meets the user’s needs.

VerificationAll QC activities through out the life cycle that ensure that interim deliverables meet their input specification


Verification

• Verification refers to the set of activities that ensure that software correctly implements a specific function, imposed at the start of that phase

• Are we building the product right?

• WHAT?


The considerations in verification planning

• The verification activity to be performed;

• The methods used(inspection, walkthrough, etc.);

• The specific areas of the work product that will and will not be verified;

• The risks associated with any areas that will not be verified;

• Prioritizing the areas of the work product to be verified;

• Resources, schedule, facilities, tools, and responsibilities.


Validation

• Validation refers to a different set of activities that the software that has been built is traceable to customer requirements

• Are we building the right product?

• HOW?


Validation methods

Black –box methods for function-based tests

• Equivalence partitioning

• Boundary-value analysis

• Error guessing.


Structural Vs Functional Testing

Structural analysis based testing tend to uncover the errors that occur during “coding” of the program

Functional analysis based tests tend to uncover error that occur in implementing requirements or design specifications


1.3 : Testing techniques

static: don’t execute the program code inspection or “walk through” symbolic execution symbolic verification

dynamic: generate test data and execute the program White-box/Glass-box Testing

• Unit Testing

• Integration/Interface Testing Black-box Testing

• System Testing

• Acceptance testing


1.3 : Testing techniques contd..

Static Testing Advantages

• Capture defects early, so saves rework cost

• Checklist-based approach

• Focuses on coverage

• Group perspective

• Highest probability of finding defects

Disadvantages• Time-consuming

• Cannot test data dependencies

• High skill levels required


1.4 Types of testing: Overview

Types of Testing• Black Box Testing

• White Box Testing

• Grey Box Testing

Levels of Testing Unit Testing Integration Testing System Testing Acceptance Testing Regression Testing


2.0 Black box Vs White box testing : Overview

Introduction:

This module discusses about the black box and white box testing and their testing techniques.

Objective:

After completing this module, you will be able to know what is white box and black box testing and the difference between them.


2.1 Black box testing: Overview

a.k.a Functionality Testing or Data-driven Testing A system or component whose inputs, outputs and general functions

are known, but whose contents or implementation are unknown or irrelevant

Black box testing techniques

Equivalence partitioning

Boundary value analysis


Identifying equivalence classes

For each external input:

1. If the input specifies a range of valid values, define one valid EC (within the range) and two invalid EC’s(one outside each end of the range).

2. If the input specifies the number(N) of valid values, define one valid EC and two invalid EC’s(none, and more than N).

3. If the input specifies a set of valid values, define one valid EC(within the set) and one invalid EC (outside the set).

4. If there is a reason to believe that the program handles each valid input differently, then define one valid EC per valid input.

5. If the input specifies a “must be” situation, define one valid EC and one invalid EC.

6. If there is a reason to believe that elements in an EC are not handled in an identical manner by the program, subdivide the EC into smaller EC’s.


Boundary-value analysis

• It is a variant and refinement of equivalence partitioning , with two major differences:1. Rather than selecting any element in an EC as being representative, elements are

selected such that edge of the EC is the subject of a test. These are always a good place to look for defects.

2. Rather than focusing exclusively on input conditions, output conditions are also explored by defining output EC’s. What can be output? What are the classes of output? What should I create as an input to force a useful set of classes that represent the outputs that ought to be produced?


Error guessing

• Its an adhoc approach, based on intuition and experience, to identify tests that are considered likely to expose errors.


2.2 White box testing: Overview

a.k.a Structural Testing or Logic-driven Testing or Glass Box Testing

Source Code is available for Testing

Structural Testing process Program Logic-driven Testing Design-based Testing Examines the internal structure of program

White box testing techniques

Basis path testing Cyclomatic complexity


2.2 White box testing contd….

White box testing is toDerive test cases: based on the program structure. to guarantee that all the independent paths within a

program module have been tested.

Minimum Criteria for White Box TestingMinimum Criteria for White Box Testing

Code High level Design Document Low level Design Document Software Requirement Specification


2.3 White box Vs Black box: Overview

Black box testing White box testing

Black Box testing is planned without the intimate knowledge of the program

White Box testing is planned with the intimate knowledge of the program

Black Box test is usually based on specification of the program

White Box testing aims at testing each aspect of the program logic


3.0 Other testing types: Overview

Introduction:

This module discusses about the other testing types like GUI testing, regression testing, configuration testing,alpha and beta testing.

Objective:

After completing this module, you will be able to what is GUI testing, regression testing, configuration testing,alpha and beta testing.


3.1 GUI testing: Overview

GUI testing GUI is the abbreviation for Graphic User Interface. It is absolutely essential that

any application has to be user-friendly. The end user should be comfortable while using all the components on screen and the components should also perform their functionality with utmost clarity. Hence it becomes very essential to test the GUI components of any application. GUI Testing can refer to just ensuring that the look-and-feel of the application is acceptable to the user, or it can refer to testing the functionality of each and every component involved.


3.2 Regression testing: Overview

Regression testing Re-execution of one or more tests in subsequent build of the

application/product to ensure

• Revisiting and testing all prior bug-fixes in response to a new fix/enhancement

• Re-testing all programs that might be affected by the fix/enhancement

• Hidden Bugs are uncovered The baseline for Regression Testing grows with every build


3.3 Acceptance testing

Acceptance testing Demonstrates that the system meets mutually agreed Acceptance criteria

• Critical Requirements

• Minimum Performance level

• Maximum Defect Detection Rate

Typically, a sub-set of System testing


3.4 Configuration and Installation testing

Configuration testing Hardware Compatibility Platform (OS) compatibility Inter-product (software) compatibility Network configuration Database compatibility

Installation testing Basic installation Installation of various configurations Installation on various platforms Regression testing of basic functionality


3.5 Alpha and Beta testing: Overview

Alpha Testing: Testing of a software product or system conducted at the developer’s site by the customer

Beta Testing: Testing conducted at one or more customer sites by the end user of a delivered software product system.


4.0 Levels of testing : Overview

Introduction:

This module is about unit ,integration and system testing.

Objective:

After completing this module, you will be able to know what is unit,integration and system testing?


4.1 Unit testing: Overview

Unit Testing Lowest Level of Testing Individual unit of the software are tested in isolation from

other parts of a program

What can be a UNIT? Screen / Program Back-end related to a Screen Screen + back end


4.1 Unit testing contd…

Unit testing activities

1.Field Level Checks Null / Not Null Checks Uniqueness Checks Length Checks Date field Checks Numeric Checks Negative Checks Default Display

2.Field Level Validation To Test all Validations for an input field Date Range Checks Date Check validation with the system date


4.1 Unit testing contd…

User Interface Checks• Readability of the controls

• Tool Tips Validations

• Ease of usage of interface across

• Consistency with the user interface across the product

• User Interface dialogs

• Tab related checks for screen controls

Functionality Checks• Screen Functionality

• Referential Integrity Checks

• Field Dependencies


4.2 Integration testing: Overview

Integration Testing

Intermediate level of testing Progressively unit tested software components are integrated and tested

until the software works as a whole Test that evaluate the interaction and consistency of interacting

components.


4.2 Integration testing contd..

Integration testing techniques Top-Down Integration Bottom-up Integration Big-bang Integration



Integration testing techniques

1. Top Down Integration Testing• Program merged and tested from the top to the bottom

• Modules are integrated by moving downward through the control hierarchy, beginning with the main control module Ref fig 1

• Modules subordinate to the main control module are incorporated into the structure in either a depth-first or breadth-first manner.

Advantages• Integrated Testing is done in an environment that closely resembles that of the

reality, so the tested product is more reliable

• Stubs are functionally simpler than drivers, and therefore they can be written with less time and labor

Disadvantages

• Core functionality tested late in the cycle



Top Down Integration Testing

Fig 1



2.Bottom Up Integration• Begins construction and testing with atomic modules (i.e., modules at the

lowest levels in the program structure.• Program is merged and tested from the bottom to top.• The terminal module is tested in isolation first, then the next set of higher level

modules are tested with the previously tested lower modules. Ref Fig 2.

Advantages• Many Programming and testing operations can be carried out simultaneously,

yielding apparent improvement in Software Development effectiveness• Unit Testing of each module can be done very thoroughly

Disadvantages• Key Interface defects trapped late in the cycle• Test drivers have to be generated for modules at all levels except the top

controlling one • We cannot test the program in the actual environment in which it will be run.



Bottom Up Integration

Fig 2



3.Big Bang Testing

A type of integration testing in which software components of an application are combined all at once into a overall system.

According to this approach, every module is first unit tested in isolation from every module. After each module is tested, all of the module are integrated together at once. Ref Fig 3



Fig 3

Module 1

System

Module 2Module 6

Module 5 Module 3

Module 4

Big Bang Integration Testing

Module 3Module 5


4.3 System testing: Overview

A Black-box Testing technique Specifications-based Testing Typically independent team testing Simulated environment testing Live/Simulated user data Tests the whole system Functional and non-functional requirements tested Business transaction-driven testing Compatibility errors uncovered Performance limitations uncovered


4.3 System testing contd…

Covers testing of the integrated system for Business functionality Performance and Scalability Usability Reliability Portability Installation Disaster Recovery


5.0 Test artifacts : Overview

Introduction:

This module discusses about the test strategy,test plan and test cases.

Objective:

After completing this module, you will be able to know what is a test plan,test strategy and test case.


5.1 Test strategy/planning: Overview

Includes Testing Objectives and Goals Test Strategy/Approach based on customer priorities Test Environment (Hardware, Software, Network, Communication etc.) Features to test with priority/criticality Test Deliverables Test Procedure – Activities and tools Test Entry and Exit criteria Test Organization and Scheduling Testing Resources and Infrastructure Test Measurements/Metrics


5.1 Test strategy/planning contd..

Benefits Sets clear and common objectives Helps prioritize tests Facilitates Technical tasks Helps improve coverage Provides structure to activities Improves communication Streamlines tasks, roles and responsibilities Improves test efficiency Improves test measurability


5.2 Test case: Overview

What is a test case? A set of test inputs, execution conditions and expected results Reflects what tests need to be performed Identifies the data needed for testing Specifies pre-conditions, post conditions and acceptance/pass criteria Provides a means to verify system use cases and other requirements Helps determine test coverage

What is a “good” test case? Has a reasonable probability of catching an as-yet undiscovered error Is sequential with the program/business flow Is not redundant Is neither too simple nor too complex Also tests the invalid and unexpected. Systematically uncovers different classes of errors with minimum (optimum)

effort and time


10.0 TCP : Overview

Introduction:

This module is about TCP.

Objective:

After completing this module, you will be able to what is TCP and its usage.


10.1 What is TCP?: Overview

What is a Test Case Point (TCP?

TCP is a measure of estimating the complexity of an application. This is also used as an estimation technique to calculate the size and effort of a testing project.

The TCP counts are nothing but ranking the requirements and the test cases that are to be written for those requirements into simple, average and complex and quantifying the same into a measure of complexity.

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Software Testing Knowledge Level: Basic. 2 ©Copyright 2004, Cognizant Academy, All Rights Reserved...

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Transcript of Software Testing Knowledge Level: Basic. 2 ©Copyright 2004, Cognizant Academy, All Rights Reserved...