This document discusses hierarchical models of software quality, including the McCall and Boehm models. The McCall model addresses three areas of software quality: product operation, product revision, and product transition. Product operation focuses on usability, integrity, efficiency, and correctness. Product revision examines testability and maintainability. Product transition considers portability, reusability, and interoperability. The Boehm model defines three levels of quality attributes: primary uses, intermediate constructs, and primitive constructs. Primary uses include as-is utility and maintainability. Intermediate constructs are flexibility, reliability, portability, efficiency, testability, understandability, and usability. Primitive constructs result in measurable properties.

1. HIERARCHICAL MODELS OF
SOFTWARE QUALITY
Muthukumaran S,
M.E. Software Engineering,
Anna University.

2. A hierarchical model of software quality is
based upon a set of quality criteria, each of
which has a set of measures or metrics
associated with it.
Quality model are,
Bohem model.
McCall model.

3. QUALITY FACTOR
QUALITY CRITERION
QUALITY METRICS
QUALITY
CRITERION
QUALITY METRICS
QUALITY CRITERION
QUALITY METRICS
A SEMANTIC HIERARCHICAL VIEW OF SOFTWARE QUALITY

4. GE model (McCall 1977&1980)
This model is aimed at system developers, to
be used during the development process.
Three area addressed by McCall’s model.
I. Product operation.
II. Product revision.
III. Product transition.

5. McCall Quality Model

6. Product Operation
Here factors are related to the Operational performance,
convenience, ease of usage and correctness.
Usability:
Ease of use of software.
Integrity:
Protection of the program from unauthorized user access.
Efficiency:
concerned with the resources.
(ex): Process time, storage.
Correctness:
The extent to which the program fulfills its specifications.
Reliability:
Ability not to fail.

7. Product Revision
These factors pertain to the Testing and
Maintainability of Software. It gives idea about
maintenance, flexibility and Testing effort
Maintainability:
The effort required locating an fixing a fault in the
program with its operating environment.
Flexibility:
Ease of making changes with its operating
environment.
Testability:
Ease of testing the program to ensure that it is
error free.

8. Product Transition
To transfer a product from one platform to another
platform or from one technology to another
technology.
Portability:
The effort to transfer a program from one
environment to another.
Reusability:
The ease of using the software in different
context.
Interoperability:
It is the effort required to couple the system to
another system.

9. Boehm Model
Boehm Model was defined to provide a set of
“well-differentiated characteristics of
software quality”.
Boehm has defined three levels of quality
attributes:
 Primary uses
 Intermediate constructs
 Primitive constructs

11. Primary uses
The high level of characteristics is made in such a way that answers
following questions:
As-Is Utility:
It defines the way a utility signifies the as-is utility. It creates a question of
how easily, reliably and efficiently an as can be utilized.
Maintainability:
This aspect decides how convenient it is to understand, change or re-
evaluate a process.
Portability:
This aspect helps in deciding an effective way to change an environment.

12. Intermediate constructs
The intermediate level of characteristics represented by the
model displays seven quality factors that altogether signify expected
quality from a software system. These are as follows:
Flexibility:
It is very easy to amend the software as per the requirement.
Parameters of the software should be so flexible that they can react
on numerous situations.
Reliability:
Software performance should be reliable with zero defects. Result
should be accurate.
Portability:
Software can run on different computer' program example DOS,
windows.
Efficiency:
Practical & efficient use of resources or data collected. Optimum
utilization of resources should be made.

13. Testability:
Software should be tested easily and as a result
users can easily check that the results are correct,
so that they can rely on result blindly.
Understandability:
Software should be simple to understand for
users so that they can use it properly and
efficiently.
Usability:
Users can apply it easily and comfortably.

14. Primitive constructs
The factors can result into creation of other measurable
properties. These are as follows:
 Device Independence.
 Accuracy.
 Completeness.
 Robustness.
 Consistency.
 Accountability.
 Device efficiency.
 Accessibility.
 Communicativeness.
 Self-descriptiveness.
 Legibility.
 Augment-ability.

15. Thank you…