Introduction
Laymen explanation
You see people praying to almighty for help when he knows that he never met to almighty. In physical world, getting someone support needs registration at first place and then the helping person should be available and understand the situation. This all requirement is challenging. If you want to understand this, then this document helps.
Technical explanation
You must have heard that "almighty stays in everyone heart". This is the key of problem solving.
Key point
almighty stays in everyone heart
Almighty who stays in someone heart is identical to the one who stays in other's heart.
How to reuse for software engineering
Copy of software stays in the user place. It is known as agent
This copy should be identical in nature
This copy should have good understanding of the user place
Reference
Personal thought