Define how to release new versions. Release notes. Marketing campaigns. Documentation and training. Distinction between system, user, customer and market. System can be continues if not (significantly) impacting UX/UI, e.g. performance improvements, security, cost savings, bug fixes, refactoring, operational automation (though internal users must be informed). Users might need to be re-trained. Customers need to plan and be informed, potentially pay for upgrade. If new product launched, then market needs to be made aware (product leadership).