Want to know the secret to a successful migration to Microsoft 365? One element stands out as most important: careful planning.

Whether you're migrating to the Microsoft cloud from on-premises or migrating between tenants as part of a merger or acquisition, planning is critical. Before you begin the first phase of migration, you need to have a complete and accurate understanding of the source environment, a clear understanding of the target environment, and a documented migration strategy.

In this article, we'll look at the main parts of an Office 365 migration and the general things you need to plan for each. We'll then move on to planning recommendations that take into account aspects such as security, scalability, and testing.

Plan Office 365 migration details

Office 365 migration is difficult in part because of the many components: Exchange, SharePoint, OneDrive, Teams, etc. Microsoft provides well-designed tools to help you migrate some of these parts. Here are proven strategies for effectively planning the major parts of an Office 365 migration.


Exchange is often the easiest part of an Office 365 migration. Most admins are very familiar with the steps involved, and the built-in tools for migrating mailboxes and permissions have gotten a lot easier over the years.

However, careful planning is necessary. Email remains an essential tool for every modern organization, and Exchange also provides other important features, especially meeting scheduling. If at any point during the migration this functionality is not available to users, the business will suffer. Therefore, it is critical to develop a thorough coexistence plan that ensures that all users can continue to send and receive email and check each other's availability, regardless of who has migrated to the new platform and who has not.

Also be sure to plan how PST files will be handled. Users like PST files because they allow them to store email messages and other Outlook items on their local computer, where they are available at any time and do not count towards their mailbox capacity on the mail server. PST files are disliked by administrators for equally good reasons: they are difficult, if not impossible, to properly back up, include in eDiscovery, and delete when required by data retention policies. What's certain is that PST files often contain important business information, and your migration plan should detail whether and how you'll move that data to the cloud. Best practices include using a third-party Office 365 migration solution to help you inventory your existing PST files, filter out data you no longer need during the migration process, and deduplicate messages that exist in both the PST file and user's mailbox.


Transferring data to OneDrive is usually simple and straightforward. However, make sure you save document versions, as well as the permissions and metadata associated with each document. A migration solution that provides filtering allows you to exclude unwanted data from your migration, speeding up the process and providing a cleaner, more manageable target environment.

The main challenge you have to consider is links, including external sharing links. They often stop functioning during migration, so it's important to develop a communication plan as well as a strategy for finding and fixing broken links. Keep in mind that digital rights may vary by platform and organization, so you'll need to have a review and approval strategy in place before re-linking.


SharePoint is much more than just a document store; Many organizations have strict SharePoint installation requirements with web parts, third-party and custom applications, and complex workflows.

Additionally, the new SharePoint experience offers many benefits that an organization can take advantage of. Migrating to Office 365 can be a great opportunity to not only move SharePoint, but also transform it into something even more powerful and useful.


Teams is one of the newest parts of Microsoft's cloud ecosystem and is rapidly growing in popularity. If you're not already using Teams, upgrading to Office 365 is a great opportunity to get started. If you're already using Teams and are migrating, such as as part of a tenant consolidation, migration is an opportunity to optimize your Teams environment.

When planning your Teams migration, start with data, including not just chats and saved documents, but any data in OneNote, calendar, and more. Be sure to also plan how you'll migrate conversations and channels, and resolve any duplicate names if you're merging clients.

What concerns businesses when migrating?

Now that we've covered some of the important details of an effective Office 365 migration plan, let's move on to concerns that apply no matter what part of the migration you're focusing on. These include security, scalability and testing.


It's critical to keep your data secure throughout the Office 365 migration process. The last thing you want is data loss or leakage. Of course, it's a good idea to back up your source environment before starting any migration, but your migration plan should include additional security precautions.

If you use manual tools and processes, you will have to handle security yourself, which is quite a challenging task. Also, be sure to think about security in the target environment. 


No migration plan would be complete without attention to project completion. Depending on the amount of data you're migrating, you may need to focus on scalability. Some migration tools can automatically distribute workloads across multiple machines to handle different migration jobs simultaneously, and some SaaS solutions can automatically scale based on platform architecture to ensure you have enough resources to complete your projects on time.


Finally, it is not enough to create and document a migration plan; you also need to test it. You will almost certainly find gaps and problem areas; 

Although testing may seem time consuming, it is a worthwhile investment. After all, when problems arise during the actual migration, they can take much longer to resolve and have serious business consequences, from downtime to security breaches.


The true measure of migration success is simple: are users happy and productive in their new environment? Proper planning is the key to answering this question positively.

For more tips on preparing for your next migration, just contact us.

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