Updating codelists on POD and SAT is not regulated. Any user who has access to codelists can go and update them. What is worse is they can update codelists that are not default version and then set their version as default.
This should be regulated in Production Environment. Atleast the codelist versions which are not of default version should be greyed out from usage. This will ensure that all Implementers and support personnel will have just default version to use as base and create a new version that would be default.
Have just default version as editable at Implementers, Support, PER resources level will ensure that always the right version of codelist gets updated. And, incorrect codelist updation gets avoided. Which means wide spread effect to all customers using the codelist is minimized or ruled out in case of a issue.
Otherwise, there will be thousands of failures and several escalations, reprocessing of documents needed. Hundreds of hours in all regions including that of management goes into RCA and eventual formalities as well.