SOFTWARE QUALITY

SOFTWARE QUALITY

UNIT - 4

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

SSLC

What is SSLC?

System Software Lifecycle – The aim to ensure quality when developing

software's.

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

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.

SSLC – LIFECYCLE STAGES

Software Requirements specification

Sotware Testing

Software Design Specification

Software Implementation

Software Maintenance and Support

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

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.

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.

1. Testing

• Helps to eliminate program errors.• Extremely difficult and Time Consuming• Introduce Fail Test Cycle – determines what will

make it failA successful Testing is one that finds errors.

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.

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.

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.