List your deployment goals and bear in mind the following factors:
- Who are your internal and external teams?
- What is the scope of the project?
- What will be the tracking mechanism of the project?
- What are the milestone dates?
Then start making decisions about the deployment:
- Make an inventory of what will be migrated from each workload to Office 365:
- Users
- Groups
- Mailboxes (if it is a mailbox migration)
- Computers (operating system, Office client version, and patches)
- File shares (if it is a SharePoint or OneDrive migration)
- Intranet sites
- Instant messaging
- Web conferencing
- Audio conferencing
- Voice
- Third-party applications that are integrated with the current systems
After you have all the data about what type of migration ...