While the project plan defines sprints leading up to delivering the completed solution on a schedule, the actual cut-over from the current situation to the new requires a more detailed go-live plan.
The go-live plan details the technical activities leading up to the planned go-live event, which cuts over from current software to the new software developed to support the new solution.
Go-live activities often start with low intensity weeks or sometimes even a few months before the actual go-live event. These preparational steps can involve upgrading infrastructure, introducing newer security protocols, rerouting data traffic through API gateways, deploying and configuring entirely newly developed applications and creating system accounts, which will be used for new system-to-system integrations and testing backup and restore procedures.
The actual go-live event is often planned around a weekend or a week with less than normal production activity, to reduce the impact of the almost always unavoidable service window, which starts with shutting down old applications and ending with new applications installed in their place.