When you are managing your environments it is best to avoid duplication in your configurations. Duplication can increase the cost of change which may reduce your appetite to make lower priority changes leading to higher technical debt. Duplication can also lead to more human error as you may make a change in only one place instead of many and in the instance where you need to roll out a change quickly duplication can slow you down.
There are different ways of removing duplication as different scenarios call for different solutions. They are grouped into categories below: