The implementation of a Process API must change.

Implement required changes to the Process API implementation so that whenever possible, the Process API's RAML definition remains unchanged

Update the RAML definition of the current Process API and notify API client developers by sending them links to the updated RAML definition

Postpone changes until API consumers acknowledge they are ready to migrate to a new Process API or API version

Implement the Process API changes in a new API implementation, and have the old API implementation return an HTTP status code 301 - Moved Permanently to inform API clients they should be calling the new API implementation