It used to define the member functions of a class outside

-Measure & Metric & Indicator

not provide enough information 

comparison of two or more measures

Compares a metric against a baseline

-To improve a process

Measure specific attributes 

of process

Develop meaningful metrics 

metrics provide indicators

Example Metrics derived:

Errors before software release, 

defects delivered to & 

reported by end-user

work products delivered

Human efforts expended

Calendar time expended

-Improving Software Quality 

& Organizational Performance

people.Product,technology

-Software measurement 

Direct Measures:Cost and effort

Line of Code & Execution Speed

Indirect Measures

Functionality,Quality

Complexity,Efficiency

Reliability,Maintainability

-1som:Derived by normalizing quality

LOC,cost,errors,defects

Effort in person-months

Number of pages&people

per kolc,per person-month

widely used but not universally 

LOC is easy to count

existing models use LOC or 

KLOC as key input

exist database on loc

But opponents argue that

dependent programming language

Can't help non procedural languages

2-Function-oriented Metrics 

measure functionality delivered 

by application as normalization value

use function point (FP)

FP’s computation is based on characteristics 

of software information domain and complexity. 

.Fp measure size computer applications

.Size measured from a functional 

.Independent computer language

.Proposed Albrecht:measure functionality 

delivered by a system

.FP can be used to:

cost effort required to design code and 

test the software

error while testing

.FP= count total x [0.65+ 0.01 x Σ(Fi)]

.Fi are Value adjustment factors

.Count total calculated

External inputs ,outputs 

inquiries & interface file

Internal logic files 

.Independent programing lang

Computation is based on subjective 

counts of information domain difficult to collect

no physical meaning

3-OO metrics used for oo projects

Set of metrics for OO projects:

Number of scenario scripts

key classes& support classes

Average number of support classes per key class

Number of sub systems 

4-Use-cases tell user visible 

functions and features.

used as normalization measure 

independent programming language

directly proportional to 

size of application in LOC & 

no. Of test cases 

no standard size

5-Software Quality Metrics

Correctness & Usability

Maintainability & Integrity