Even though Microsoft will handle the heavy lifting of standing up, patching, and managing the systems, there are still some elements of work needed to maintain the service.
Managing the portal:
Service Health Dashboard: Always know the current health of your Office 365 services, and view detailed information about current and past issues.
Monitoring the Internet connection.
- Identify problem network nodes anywhere between your users and Microsoft
- Diagnose network issues affecting packet loss, SSL negotiation, and DNS resolution
- Compare local ISP performance v. historical data as well as other providers