Quality assurance aims to identify and correct errors early in the development process through reviews and testing at each phase. The System Software Lifecycle (SSLC) model aims to ensure quality when developing software. It has five stages: requirements specification, design specification, testing and implementation, and maintenance and support. Testing is an important but difficult part of development that helps eliminate errors by determining what causes failures. Validation and certification ensure the software meets standards through simulated and live testing. Maintenance provides adjustments to comply with specifications and improve quality through problem reporting and resolution.

1. SOFTWARE
QUALITY
UNIT - 4

2. Quality Assurance
Quality assurance deals with the
objective of the project and reviews the
overall activities so that errors are corrected
early in the development process.
Steps are taken in each phase to ensure
that no errors are found ultimately in the final
software

3. SSLC
What is SSLC?

4. System Software Lifecycle – The aim
to ensure quality when developing
software's.

5. Quality factors
• Correctness – extent to which Program meets
the aim
• Reliability - the degree to which the system
performs its intended
functions over a time.
• Efficiency - Amount of Computer resources
required
• Usability - efforts needed to learn and
operate
• Maintainability - Errors located& Corrected
• Testability - to test a program

6. Quality factors
• Portability - transporting a program
from hardware to the
other…..
• Accuracy - the required Precision in
input editing,
computations and output.
• Error Tolerance - Error detection versus
error avoidance
• Expandability - Ease of adding databases
• Access control and audit - Extent to which access can
be audited.
• Communicativeness - How descriptive or useful
the inputs and outputs
are explained.

7. SSLC – LIFECYCLE STAGES
Software
Requirements
specification
Sotware Testing
Software Design
Specification
Software
Implementation
Software Maintenance and Support

8. STAGE 1 : SOFTWARE REQUIREMENTS
SPECIFICATION
• The goal of this stage is to generate the required
document which provides the technical
specifications for the design and development of
the software.
• Accurate Document enhances the system quality
– By formalizing the communication between the
system developer and user

9. STAGE 2 : SOFTWARE DESIGN SPECIFICATION
• This stage defines the overall architecture of the
software.
• It provides the functions and features described
in the software requirements document.
• It defines the logical subsystem and their
respective physical modules.

10. STAGE 3 & 4 : SOFTWARE TESTING & IMPLEMENTATION
• Testing is to ensure the completeness and
accuracy of the system and minimize the resetting
process.
• Implementation stage is to provide a logical order
of creation of modules.

11. 1. Testing
• Helps to eliminate program errors.
• Extremely difficult and Time Consuming
• Introduce Fail Test Cycle – determines what will
make it fail
A successful Testing is one that finds errors.

12. 2. Validation
• Checks the quality of software in both simulated
as well as live environment.
• Alpha Testing and Beta Testing will be handled in
this stage.
After the scheduled time failures and errors are
documented and corrections & enhancements
are made before the package is released for use.

13. 3. Certification
• To certify that the program or software is current
and confirms to standards.
• Testing specialist will review and determine how
well it meets the vendor’s claim.
• Certification is issued after the testing procedure
is done.

14. STAGE 5 : SOFTWARE MAINTENANCE AND
SUPPORT
• To provide necessary software adjustment for the
system to comply with the original specifications.
• To develop a procedure for correcting errors
• To Improve quality assurances by encouraging
completing recording and lodging of problems.
• To ensure that reported problems are promptly
forwarded to the appropriate resolver.