Product metrics

Points covered :

What is metrics

Challenges of product metrics

Measurement principles

Software metrics and Qualities

McCall’s Factors

ISO 9128 Standards

PRODUCT METRICS

SOFTWARE MEASUREMENT-???• Measurement is fundamental to any engineering discipline, and software

engineering is no exception.

• What is it?

Software process and product metrics are quantitative measures that enable software people to gain insight into the efficacy of the software process and the projects that are conducted using the process as a framework.

• Who does it?

Software metrics are analyzed and assessed by software managers. Measures are often collected by software engineers.

• Why is it important?

If you don’t measure, judgment can be based only on subjective evaluation. With measurement, trends (either good or bad) can be spotted, better estimates can be made, and true improvement can be accomplished over time.

WHY SOFTWARE METRICS???

• To characterize.• To evaluate.• To predict.• To improve.

• Characterize-

To gain understanding of processes, products, resources, and environments

• Evaluate

To determine status with respect to plans

• Predict

To plan

• To Improve

MEASUREMENT METRIC AND INDICATOR

• Measurement is the act of determining a measure.

• The IEEE Standard Glossary of Software Engineering Terms [IEE93] defines metric as

“a quantitative measure of the degree to which a system, component, or process possesses a given attribute.”

• An indicator is a metric or combination of metrics that provide insight into the software process, a software project, or the product itself

MEASUREMENT PRINCIPLES

• Formulation : the derivation of software measures and metrics appropriate for representation of software

• Collection : mechanism used to accumulate data required to derive the formulated metrics

• Analysis : the computation of metrics and the application of mathematical tools

• Feedback : recommendations derived from interpretations of product metrics transmitted to the software team

METRICS CHARACTERIZATION AND VALIDATION

• Should have desirable mathematical properties

• The value of the metrics should vary as per the traits

• Metrics should be validated empirically in a wide range of context before being published or used to make decisions

GOAL-ORIENTED SOFTWARE MEASUREMENT

Goal/Question/Metric paradigm is a technique for identifying meaningful metrics for any software process .

Highlighted points are :

• Establish an explicit measurement goal

• Define a set of questions that must be answered in order to achieve the goal

• Identify well formulated metrics that help to answer the question

ATTRIBUTES OF SOFTWARE METRICS

• Practical support is expected

• Measurement demands should be simple

• Less esoteric and easy to understand for real world professionals

• Should specify the basic intuitive notion of a high-quality software

• Derived metrics and measures should lead to simple and computable conclusions

• Easy to derive the metrics and should not demand inordinate effort or time

THE PRODUCT METRICS LANDSCAPE

Landscape of a metrics gives you the various aspects and key points of the model and what exactly the metrics includes :

N.B. : please lick your TECH-MAX for this !!!

SOFTWARE QUALITYSoftware quality is the conformance to explicitly stated functional and performance requirements , explicitly documented development standards and implicit characteristics that are expected of all professionally developed software

• Software requirements are reference from which quality is measured, lack of conformance is lack of quality.

• Specified standards define a set of development criteria that guide the manner in which software is engineered

• There are some implied requirements which are must with specified

criteria

• There are some software quality standards developed based on the

above points yet they vary as per applications and users of the software.

MCCALL’S QUALITY FACTORS

Directly measured factors

Indirectly measured factors

Product Revision

Product Transition

Product operation

MaintainabilityFlexibilityTestability

PortabilityReusabilityInteroperability

Correctness

Reliability

UsabilityIntegrity

Efficiency

McCall’s Quality Factors

I.S.O. 9126 QUALITY FACTORS

The six standard attributes that are involved are:

• Functionality

• Usability

• Maintainability

• Portability

• Reliability

• Efficiency

BUSINESS PROCESS FOR QUALITY DEVELOPMENT

WHY TO HAVE QUALITY CHECK WITH PRODUCT METRICS???

• Deliver performance

• Restrict Under-Quality

output.

• Customer satisfaction

PERFORMANCE MATTERS!!!

TYPICAL QUESTIONS• Define software quality

• ISO Factors

• Steps for Effective measurement

• Explain the factors in McCall restriction

• Product metrics landscape

• Goal oriented measurement

• Distinguish between Measure and Metric