Disclaimer: The opinions expressed herein are my own personal opinions and do not represent my employer's view in any way.
from p.28 of "The Pragmatic Programmer" 2nd Edition
Code that is ETC (Easy To Change) - is the essence, the goal of just about all software design guidance.
from p.262 of "The Pragmatic Programmer" 2nd Edition
The reason code must be ETC is to enable us to adjust to changing business requirements.
i.e. ETC software enables us to be agile.