Quality matrices.
Person Month (PM):
If a person works for one monh = 1PM
so if 5 person workfor 12 months total PM will be
5 X 12 = 60 PM
So if we know the complexity of a project in PM we can easly calculate the total effort required for the execution of project.

Product Metrics:
Used to estimate the size of the project. There are two different types of methods available
(I) KDSI - Kilo 0r Thousand delivered source instructions.
(II) KLOC - Kilo Lines of Code.
On the basis of this we categorize a project in small, intermediate, medium and large.
Small <= 2KDSI
Intermediate > 2 & <= 8 KDSI
Medium > 8 & <= 32 KDSI
Large > 32 & <= 128 KDSI
Very Large > 128 KDSI

Productivity Metrics:
DSI = delivered source instructions
Calculated as no. of lines written by the programmer per hour.
We can calculate the size of project using KDSI ad DSI.
Time required for the project hours = Total KDSI of the project / Avg. DSI