Speed up your maven build

Imagine a company having 10 modules each depending on the other. Lets say building it would take 15 minutes using maven. 
So the team would spend roughly in a day - (noOfBuildTimesPerDay x 15 minutes) x developerCount. This is bad.


Some options :
"mvn clean install" is good for small/medium sized projects but not for bigger ones.

Trade-off between time and space is always there. When space is not a major constraint , we can gain time by

"mvn clean install  -Dmaven.compile.fork=true  -Dmaven.junit.jvmargs=-Xmx512m -Dmaven.junit.fork=true"

With mvn clean, delete on windows is slower, instead if we rename it could boost the build time.
http://bosy.dailydev.org/2009/02/speed-up-your-maven-build-four-times.html

This cut the build time by around 30% on my PC. Thats an improvement isnt it.

I think it would be a big improvement if maven can reuse the classes generated by 
eclipse. Also having an exploded war deployment is an option to reduce pack and unpack times.

Ref:
http://stackoverflow.com/questions/161698/how-can-i-speed-up-my-maven2-build