Software Quality

SOFTWARE QUALITY
 MARIA KHALID ROLL NO.63
 JAVERIA RASHID ROLL NO.36
 DANIAL MIRZA ROLL NO. 85.
 JAHANGEER QUERSHI ROLL NO.78

AGENDA
1.What is Quality?
2.What is Software Quality Assurance?
3.Components Of Quality Assurance.
4.Verification and Validation

What is software?
According to the IEEE
Software is:
“Computer programs, procedures,
and possibly
associated documentation and data
pertaining to
the operation of a computer system”.

What is Software quality?
 Low levels of defects when deployed,
ideally approaching zero
 High reliability, or the capability of
running without crashes or strange
results
 A majority of clients with high user-
satisfaction when surveyed

What is Software Quality?
1.Accroding to computer literature
Quality means “Meeting
Requirement”.
2.The product has something that other
similar products do not that adds
value. (Product based Definition).

Why the quality is
important?
 Why business should be concerned
with quality:
 Quality is competitive issue now
 Quality is a must for survival
 Quality gives you the global reach
 Quality is cost effective
 Quality helps retain customers and
increase profits
 Quality is the hallmarks of world-class
business

Software Quality Factors
 Correctness
 accuracy, completeness of required output
 upto-dateness, availability of the information
 Reliability
 Minimum failure rate
 Efficiency
resources needed to perform software function
 Integrity
 software system security, access rights
 Usability
 ability to learn, perform required task

Software Quality Factors
 Maintainability
 effort to identify and fix software failures (modularity,
documentation, etc)
 Flexibility
 degree of adaptability (to new customers, tasks, etc)
 Testability
 support for testing (e.g. log files, automatic diagnostics, etc)
 Portability
 adaptation to other environments (hardware, software)
 Reusability
 use of software components for other projects
 Interoperability
 ability to interface with other components/systems

Software Quality Assurance
 Systematic activities providing evidence of
the fitness for use of the total software
product.
 It is achieved through the use of
established guidelines for quality control to
ensure integrity and prolonged life of
software.
 It is a planned effort to ensure that a
software product fulfils criteria and has
additional attributes specific to the product.

 It is the collection of activities and
functions used to monitor and control a
software project so that specific objectives
are achieved with the desired level of
confidence.
 It is not the sole responsibility of the
software quality assurance group but is
determined by the consenses of the project
manager ,project leader, project
personnel, and the users.
Software Quality Assurance

Components of Quality
Assurance

Software Testing
 Software testing is a popular risk
management strategy.It is used to
verify that functional requirements
were met.
 The major purpose of verification and
validation activities is to ensure that
software design, code, and
documentation meet all the
requirements imposed on them.

Verification and validation
 Software Verification and
Validation
 When Combined Together Are
Abbreviated as V & V

Verification of software
 Verification is the process confirming
that -software process meets its
specification
Verification Ensures that:
Every Step in the Process of Building
the Software Delivers the Correct Product

Validation of software
 Validation is the process confirming
that it meets the user’s requirements.
Validation Ensures that:
Software Being Developed or Changed
Satisfies Functional and All Other
Requirements

Major Categories of Verification
 There are Two Major Categories
of Verification Testing:
• Dynamic
Testing
• Static Testing

Dynamic testing
 What Does Dynamic Testing Do ?
• Involves Execution of a
System or Component
• Selection of a Group of Test
Cases Consisting of Test
Data
• Finding out Output Test
Results out of Input Test
Cases

DYNAMIC TESTING
 Sub Categories of Dynamic Testing
• Functional Testing
• Structural Testing
• Random Testing

Dynamic testing
 Functional Testing: A Type of
Dynamic
Testing
• Involves Identification & Testing of all Functions
of the System as Defined in Basic Requirements
Documents
• It is a Black Box Testing Not Expecting that the
Tester should have any Knowledge of the Basic
Code & Implementation of the System
• It uses Test Cases Designed to Investigate Certain
Feature of the System

Dynamic testing
 Structural Testing: A Type of Dynamic
Testing
• It is a White Box Testing Expecting Full knowledge
of the Implementation of the System
• Information of the Internal Structure of the
System is Used to Design Tests for Checking the
Function of Individual Components
• Like Functional Testing, it also uses Test Cases
Designed to Investigate Certain Feature of the
System

Dynamic testing
 Random Testing: A Type of Dynamic
Testing
• Uses Free Selection of Test Cases out of a set of
All Possible Test Cases
• Uses Randomly Decided to Detect Faults which
Go Undetected by Other Systematic Testing
Techniques
• Exhaustive Testing is a Form of Random
Testing, Involving Input Test Cases having
Every Possible Set of Input Values

Static testing
 Does not Involve Operation of
the System or Component
• Consistency Techniques
: Meant for Doing Analysis of Consistency
• Measurement Techniques
: Meant for Doing Measurement of Some
Property of the Program

Static testing
 Consistency Techniques of Static
Testing
# Correct Typing
# Correct Requirements and Translation of
Specifications
# Correct Syntax
# Correct Parameter Matching between procedures

Static testing
 Measurement Techniques of Static
Testing
Measures the System Properties
Like:
# Being Error Prone
# Being Understandable
# Being Well Structured

Validation of software
 Validation comes Into Picture
at the End of the Development Cycle
• It Views the Complete System
Exactly Opposite of
Verification
• It Focuses on Smaller Sub-
Systems

Techniques of Validation
Testing
 Formal Methods :
A Technique of Validation Testing
• Besides being a Verification Technique
it is a Validation Technique as well
• Involves use of Mathematical and
Logical Techniques to: Express,
Investigate, & Analyze the
Specification, Design, Documentation
and Behavior of Hardware as well as
Software

Testing
 Fault Injection :
Is an Intentional Activation of Faults by
Either Hardware or Software to Observe
the System Operation under such Faulty
Situations

Testing
 Hardware Fault Injection :
Also known as Physical Fault Injection
since Faults are Injected into the
Physical Hardware

Testing
 Software Fault Injection :
• Involves Injection of Errors into the
Computer Memory through some
Software Techniques
• It is a sort of a Simulation of Hardware
Fault Injection

Testing
 Dependency Analysis :
Involves Identification of Hazards and
Subsequently Proposing Methods to
Reduce the Risk of the Hazards

Testing
 Hazard Analysis :
Involves using Instructions to
Identify
Hazards, Their Root Causes , and
Possible Countermeasures

FOR YOUR ATTENTION AND TIME…….

Software Quality

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