What are the stages in the system evolution process and what triggers that process?

What are the stages in the system evolution process and what triggers that process?
Answer: Release Planning, Change Implementation, System Release, Impact Analysis, Change Requests, Platform Adaptation and System Enhancement.

            System change proposals are the driver for system evolution in all organizations. Change proposals may come from existing requirements that have not been implemented in the released system, requests for new requirements, bug reports from system stakeholders, and new ideas for software improvement from the system development team.