After some operations my sandbox is broken (database became inconsistent, some services do not work, etc). How to reinstall the sandbox and start from scratch?
You can redeploy your sandbox using self-service portal on http://dev.apsstandard.org.
Click on SANDBOXES, choose 'provision/reprovision' action and specify the versions of Operations Automation (and Business Automation if applicable) you would like to be installed.
Redeployment can take between 1 and 4 hours depending on configuration of your sandbox.