Inner engineering 
is a science which is created by sadhgur.. the way we have a tools to manage outside world.. similarly we need some thing which can create pece, love, pleasure inside us. My experience was fantastic after doing inner inginnering, i can feel peace, and growth as a humanbeing, it is a fantastic tool given by sadhguru. You can watch sadhguru videos on youtube. Now a days in the name of yoga of people are doing just a physical exercise but yoga is more than a physical exercise in inner engineering sadhguru also teach ancient yoga.. which is very experiencal.. after doing ancient yoga. You can feel change and experience  it

http://www.ishayoga.org/

Why should any one do inner Enginnering:mostly we are not aware about mental health, mental healh is very neseccary, inner engineering gives mental health,  clearty in life, inner engineering is life time return  investment.