The Rule of Three

Internal

• Software Engineering
• DRY
• Designing Modular Systems

Overview

The "rule of three" for software reuse suggests the you should turn something into a reusable component when you find three places that you need to use it.

https://blog.codinghorror.com/the-delusion-of-reuse/ Facts and Fallacies of Software Engineering https://www.amazon.com/exec/obidos/ASIN/0321117425/