All maintenance requests are visible in the OPERATIONS module - Service requests.
The left column shows new service requests.
The middle columns show service requests that are in the process.
The right column shows resolved/closed ones.
For each of the service requests, you can delegate to the responsible company (up or down).
Set status as in progress or closed that are already resolved.
Send a message to the one who reported the issue.
Tip: You can also simply drag and drop between the 3 mentioned columns.