Purpose

To make good Changes and SOP's (Standard Operating Procedures) - its similar to being a chef that need to learn how to make a good dish, or a marine that need to perform a certain function really good, as in: repetition, repetition....

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So final step is to make the SOP:

Divide and conquer

The Divide and conquer principle is crucial for good Changes and SOPs - as opposite to havin a big Change with many steps and types of implementation (Application, Firewall, Database, OS), You should divide the Change into smaller Changes that are independant and/or sequentiel to be done separately. This also means that a rollback of a Change is not highly critical for the complete scope of the Changes.