C4 : Product and Process Quality (Product Quality Models (McCall (Steps,…
C4 : Product and Process Quality
Software Product Characteristic
SW is developed/engineered, not manufactured
Software does not wear out but only deteriorates, need enhancement
Assembled from reusable component instead of build from the start
The complete set of computer programs, procedures and possibly associated documentation and data designated for delivery to a user
Standards and practices act as mean to measure conformance which will be used to measure quality
Product Quality Attributes
Easy to use?
Required function available?
Easy to modify?
Perform function correctly?
Easy to transfer to another environment?
Product Quality Models
To evaluate software product quality
To define the characteristic to be assessed and suggest some measure to capture those characteristic
Quality are described using
of quality from user's perspective
Focus on the final product (executable code)
Assumes quality factor are still to high level to be meaningful or to be measurable directly
into lower level attributes
A high level external or internal attributes
ISO 9126 Model
A universal model ease comparison
Use McCall model as the basis for international standard for software quality measurement
Defined as "The totality of features and characteristic of a software product that bear on its ability to satisfy stated or implied needs"
Quality are decomposed into 6 factors
Goal Question Metric Model
Derived metrics from measurements goals and question , usually related to characteristic
Define Your Own Model
Design by measurable objective
Decompose high level feature to a more measurable attributes
Engineer will deliver software result incrementally to user based on the importance of the functionality
User identify key software attributes to assign function priorities
Measured by based the process to a standard or model
Process Quality Model
ISO 9001 Quality Management for Process Quality Framework
Roles in Product Evaluation
Independent assessment of a production process
Only show general guideline that help to ensure that all reasonable steps have been taken to encourage process quality
By SEI of Carnegie Mellon University
Use as the basis of process improvement and evaluation
If the quality of process for developing a software is good, then there is a reasonable assurance that the product quality is good
Software Development Specifics