How to Master Your Office 365 Tenant Migration — Top 5 Lessons Learned

More and more organizations today are taking advantage of the many benefits of the Microsoft cloud. What’s your favorite benefit? The easy scalability? The improved business agility? The ability of users to work anywhere at any time? The simple licensing model and predicable costs? Or maybe it’s having someone else shoulder the burden of ensuring 24/7 platform availability and performance!

Of course, you’ve undoubtedly discovered that moving to the cloud doesn’t leave you with nothing to do. If you’re reading this blog, you’re probably facing a merger, acquisition or similar scenario that means you have to find a way to migrate users, Exchange mailboxes and OneDrive data from one tenant to another — and it’s up to you to do it quickly, safely, completely and with minimal impact on the business.

It might feel like a daunting task. After all, Microsoft has always made it a point to keep each customer’s tenant strictly separate in order to ensure security, and now you have to somehow scale those high walls and integrate two tenants into one.

Breathe. You’re not in this alone. Many organizations have already performed Office 365 tenant to tenant migrations, and you can learn a lot from them. In fact, at a high level, you should approach an Office 365 tenant migration much the same was any other migration project, such as an Office 365 migration. I’ve talked with lots of Quest customers as well as Quest’s own migration experts, and I’ve taken the liberty of boiling it down to these key 5 lessons learned:

1.  Get a complete and accurate inventory of your source environment.

It might sound obvious, but you need to build a complete inventory of the accounts and data that you want to migrate. No problem, you might say; after all, it’s a fairly simple process to get a list of all accounts in Active Directory and Azure AD, for instance.

But pay attention to that little clause at the end: “that you want to migrate.” You don’t want to migrate absolutely everything from the source tenant to the target; migrating stuff you don’t need would slow your project, increase risk, and clutter up your target environment, making it hard to manage and secure. So remember that this task is not entirely technical; it must also involve conversations with your business counterparts. Not only will they help you eliminate unnecessary data from the migration, they might also help you discover thing, such as email archives or OneDrive data, that you didn’t know about but that you actually need to include in the project.

2.  Have a good coexistence plan from the start.

Few migrations happen in one big bang; most take weeks or months. If you expect to simply put the business on hold for the duration, you’re in the wrong line of work. You need to ensure that users can remain productive throughout the entire migration — emailing colleagues, sharing data and scheduling meetings without having to worry about which accounts and data have been migrated and which have not. Behind the scenes, that means synchronizing email systems, data shares, calendars, free/busy data and more.

In fact, in most cases, it’s the end-user experience that management weighs most when assessing the success of the migration. (You might have experienced this firsthand when you were migrating to Office 365.) Therefore, be sure to make seamless coexistence a top priority from the very beginning of your project.

3.  Communicate effectively before, during and after the migration.

Ensuring a good user experience requires more than just a strong coexistence plan, however. Good communication is also critical. It’s easier if you break it down into three areas: who & what, when, and how:

  • Who & what — Determine exactly who is responsible for performing which types of communication, and exactly what each group of users needs to know. For instance, the IT manager might provide company-wide emails about the purpose of the migration and the expected timeline, while training staff might be responsible for ensuring end users know how to log on with their new credentials. Whenever possible, enable people to get the information they need themselves, for instance by giving managers a dashboard they can go to whenever they want to know the current status of the migration.
  • When — At the start of the project, be sure to provide everyone with the migration timeline, where they will find resources to support them, and the methods for reporting and tracking issues. During the migration, provide a regular status updates.
  • How — Take advantage of all appropriate options for how to communicate, whether that’s regular email blasts, FAQs in a designated place or a dedicated migration hotline.

4.  Be ready for the unexpected.

Although I don’t subscribe to Murphy's Law — the idea that anything that can go wrong will go wrong — I do think it’s smart to plan for the possibility that a few things will go wrong, especially in a project as complex as a migration. After all, something as simple as a misdirected email could result in users being migrated before they’re ready, or there might be corrupted data that you didn’t catch soon enough, or a brief connectivity issue that keep a migration job from completing correctly. So make sure you can roll back any migration job quickly. Again, your primary goal is to minimize the impact to users.

Also be sure that your backup and recovery solution provides a quick and easy way to identify changes and granularly restore objects if necessary. Remember that many solutions can’t handle cloud-only groups or business to business (B2B) or business to consumer (B2C) accounts. And, of course, ensure you have a broad, robust backup and recovery strategy in case a major issue arises.

5.  Consider the ABC’s of security.

It’s critical to think about security both during and after the migration. Here are the ABCs to focus on:

  • A is for audit — To minimize the risk of a data breach or other security incident, you need to keep an eye on what users are doing and whether the platform is working correctly. There are some native auditing capabilities, but it’s smart to consider investing in a third-party solution that delivers broader functionality and, ideally, provides a unified view of both your cloud and on-premises environments.
  • B is for backup — Microsoft is responsible for ensuring the uptime of your Office 365 environment, but there's no native backup of data. Yes, the Azure AD Recycle Bin is handy, but it doesn't cover all objects and it can’t help you restore individual attributes of an object. You really do need an enterprise backup, recovery and disaster recovery solution.
  • C is for control — You also need to ensure that all access rights are granted in accordance with the least-privilege principle and accounts are deprovisioned in a timely manner. With native tools, exercising proper control is difficult, time-consuming and error-prone, so it’s smart to invest in an enterprise identify management solution that will automate and streamline the job.

Ready to learn more?

These five lessons learned are a great place to start preparing for any migration, but you really should take the time to go both broader and deeper. Check our new ebook, “Don’t just survive Office 365 tenant migration — master it!” for additional best practices for a tenant-to-tenant migration, as well as specific best practices for account migration, mailbox migration and OneDrive migration.

Download the E-Book