The enhancement framework used by SAP comes with the Business function switches.
The Enhacement packages (EHP1 and EHP2) brings the switches in
mutiple areas. A few interesting areas I have covered in earlier posts.
The advantage of the switches is the customer can pick and choose the functionality also can utilise the SAP delivered solutions to meet their requirements.
If you are the upgrade customer or the consultant you may like to consider these switches to be implemented along with scenarios (for example - SSP,Strategic sourcing, MDM catalog) to bring the new functinality features.
The most of the switches are irreversible and can not be reverted back except a few. Hence customer should implement these switches in their Sandbox environment and test thoroughly.