Your ultimate goal is to ensure that the service is at the latest version.
There are numerous dependencies to that task - one of which may be stopping the service before upgrading. There are dependencies to stopping the service - maybe telling the load-balancers or your monitoring system. When the service has been upgraded, you can trigger notifications that other items within your config can depend upon (for example, when an upgrade is complete, restart the service, when the service restarts, add it back to the monitoring system etc).
All of these can be modelled in these config-management tools, as explicit dependencies within your manifest file - as opposed to implicit and ad-hoc dependencies within your script.
There are numerous dependencies to that task - one of which may be stopping the service before upgrading. There are dependencies to stopping the service - maybe telling the load-balancers or your monitoring system. When the service has been upgraded, you can trigger notifications that other items within your config can depend upon (for example, when an upgrade is complete, restart the service, when the service restarts, add it back to the monitoring system etc).
All of these can be modelled in these config-management tools, as explicit dependencies within your manifest file - as opposed to implicit and ad-hoc dependencies within your script.