Self service requires information, which requires design
Consider travel as an example:
If you've arranged the flights on the monitor in order of flight time, not destination, requiring me to stop and take out my ticket, you have failed.
If you've hidden the room numbers (or given them fancy names) so that only an employee can find the right spot, you've failed as well.
The label on prescription drugs, the instructions post-doctor visit, the manual for using software or putting together furniture--if we're getting rid of service and turning it into self-service, we owe it to our newly deputized employees (our customers) to give them the tools they need to not need us.