There are a number of tools that help assess software attributes, I can suggest IBM's rational quality manager. You may read more about it at:

https://www.ibm.com/developerworks/rational/library/software-quality-challenges-practice-recommendations/

Further down the road, you might want to focus on software testing methodologies such as whitebox/blackbox/greybox or unit et cetera and their effects on perception of quality.

Software Quality and Standards (Dr. James A. Bednar and Dr. David Robertson)

Software Engineering Standards

According to the IEEE Comp. Soc. Software Engineering Standards Committee a standard can be:

• An object or measure of comparison that defines or represents the magnitude of a unit

• A characterization that establishes allowable tolerances or constraints for categories of items,

• A degree or level of required excellence or attainment SEOC2 Spring

Systems Engineering Standards

Particular application domains develop sophisticated interactions between system and software engineering, so standardizing from a systems point of view can be

beneficial. Examples:

Lifecycle: ISO/IEC WD 15288 System Life Cycle

Processes

Requirements: IEEE Std 1233-1996 Guide for Developing System Requirements Specifications

Project Management Standards

These are concerned with how general principles of good management are applied to specific areas of software engineering.

Examples:

General project management: IEE Std 1058.1-1987 Standard for Software Project Management Plans

Producing plans: IEEE Std 1059-1993 Guide for Software Verification and Validation Plans

Thanks @ Wiem Khlif.

Are these standards available free online? My work concern with quality attributes such as security, usability, flexibility standard such as ISO 9126. Any quality standards available free online for research purpose?

Thanks @ Santosh J. Dubey

There is the ISO/IEC 250XX Series Standard for Systems and Software Quality Requirements and Evaluation, but unfortunately it is not available freely.

At least a list of terms and short descriptions for quality properties can be seen in the following preview of the ISO/IEC 25010:

https://www.iso.org/obp/ui/#iso:std:iso-iec:25010:ed-1:v1:en

Since the whole series was to costly we only bought the parts regarding the Measurement of those quality properties:

• ISO/IEC 25022:2016: Measurement of quality in use
• ISO/IEC 25023:2016: Measurement of system and software product quality
• ISO/IEC 25024:2015: Measurement of data quality

Thanks @ Michael Krisper