Sofware Metrics is a process of Measuring the software 
quality.

Measurement is fundamental to any engineering discipline
Why Metrics?
- We cannot control what we cannot measure!
- Metrics helps to measure quality
- Serves as dash-board

The main metrices are :size,shedule,defects.
In this there are main sub metrices.

Test Coverage = Number of units (KLOC/FP) tested / total 
size of the system
Test cost (in %) = Cost of testing / total cost *100
Cost to locate defect = Cost of testing / the number of 
defects located
Defects detected in testing (in %) = Defects detected in 
testing / total system defects*100
Acceptance criteria tested = Acceptance criteria tested / 
total acceptance criteria

metric is a mathematical number that show the relationship 
between two variables.

software metric is a measure used to quantify the 
software,software development resources and software 
development process.
 the are two types of metrics.
process and product metrics.

path tested=no of paths tested/total no of paths.

an important software metric is total no.of defects found 
in system internal testing against the no of defects found 
in the user testing.

Mesure the charecterstics of project scheduled,Project 
plan,testcases.
There are thee type of Matrix
1-QAM
2-TMM
3-PCM

Metrics is a mesurement.The aim of this one is to measure 
the quality of the application.
it represents the final out come of the testing
metrics represents as belows
No.of test cases design per day
No.of defects findout per day
No.of test cases are executions per day
Reviews etc...
Metrics are 6 types

1)	Stability Trend Chart.
2)	Defects for Module
3)	Defects for Tests
4)	Test Coverage
5)	Defects for KLOC
6)	Defects for Testing Environment