In my findings (https://developer.atlassian.com/display/JIRADEV/JIRA+Plugin+Lifecycle), the LifecycleAware onStart method seems to be called after PluginEnabledEvent occurs when starting up JIRA, but well before PluginModuleEnabledEvent when installing/enabling a plugin.

This lack of consistency in timing makes it difficult for plugin developers to write useful code for the LifecycleAware onStart method.