Unless if you have to go back and keep on fixing it again and again and again and again... until one day, the cost of fixing (please also include the cost of re

Unless if you have to go back and keep on fixing it again and again and again and again... until one day, the cost of fixing (please also include the cost of re-testing) can't be justified any longer. Anyhow, that's why software should be developed in modules/components.