SharePoint migration best practices: take your customizations and applications to the cloud

4 min read
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Office 365 is currently the most popular cloud productivity platform on the market, and much of that uptake has been driven by SharePoint Online. At the SharePoint Virtual Summit in May 2017, it was revealed that more than 250,000 organizations and over 85% of Fortune 500 companies have SharePoint as part of Office 365.

If SharePoint Online is part of Office 365’s appeal, part of SharePoint’s appeal has always come from its potential to be expanded upon, taking the functionality of the platform to even greater heights. There are now thousands of SharePoint extensions, customizations and applications created by Microsoft Partners from around the world to further improve the platform and empower workers, from web parts to workflows to user interface enhancements.

SharePoint customizations and applications have been around almost as long as SharePoint itself. However, now that Microsoft has turned its focus on the cloud, many were built (and are based) on-premises. Bringing the benefits of your customizations and applications into the cloud requires migration, but it’s not a straightforward task. So, in this post, we’re going to look at SharePoint migration best practices when it comes to migrating your customizations and applications.

Are you thinking about planning a migration project? Check out Rencore’s migration best practice checklist.

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Barriers to migrating customizations and applications

Just like a content migration, migrating your SharePoint customizations and applications to the cloud can be a lengthy, complex and tedious process. On-premises SharePoint customizations and applications that are migrated to SharePoint Online without proper consideration aren’t going to function in the same manner (or worse, they won’t work at all) in the new environment. Yet your workers are likely to expect to use the customizations and applications they relied on to get their work done on-premises. Because of this, they may be thrown off if when moving to SharePoint Online they only have the basic SharePoint interface when they get there.

Microsoft manages SharePoint Online and Office 365 centrally. That means you aren’t given as much control over the platform’s code. So, certain methods for customization that work in SharePoint Server 2007, 2010, 2013 or even 2016 won’t necessarily work in SharePoint Online. SharePoint Online is continuously being improved centrally by Microsoft, and therefore any custom code that you have implemented may be affected when updates roll through.

Furthermore, any customizations and applications that affect the underlying SharePoint Online code are unlikely to work in the cloud. This is especially true for sandboxed solutions, as Microsoft point out:

Sandboxed solutions carried over as part of a migration will continue to work for a limited period; however, Microsoft is focusing on alternative solutions for SharePoint Online and it is highly recommended that all Sandboxed solutions be replaced with alternative functionality such as online apps.

It’s important to mention that sandboxed solutions with code artifacts that contain event receivers, web parts, etc. will not work at all regardless of migration.

This means that many server-side customizations and applications, particularly sandboxed solutions, cannot be migrated without further changes being made first. But this shouldn’t stop you from migrating. You’ve likely already spent a lot of time, effort and money on your on-premises SharePoint customizations and applications, and your employees are reliant on them, too.

So, if you’re moving to the cloud, you have two options: you can let that investment go to waste, or you can modernize your customizations and applications, and get them ready for the cloud.

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SharePoint migration best practices with Rencore

Many organizations live in fear of a content migration until they realize there are external parties that can relieve much of the burden. They can help you plan and prepare, help organize your content at both the source and destination, and minimize risk to make the process much easier. At Rencore, we developed Rencore for Modernization to make the same true for SharePoint customizations and applications. Our unique tool can cover the entirety of your customization and application migration in just five steps:


First you select which customizations and applications you would like to include in your analysis, then you run an analysis. A report is then generated on your SharePoint solutions. You are then provided with a comprehensive summary, including complexity, dependencies and expected effort to migrate to SharePoint, so you can plan next steps.


Once you’ve chosen which customizations and applications you want to migrate, our software will offer guidance on the best way to proceed. The tool analyzes the customization’s components and how they will be affected by a transformation so you know what’s in store.


After analyzing the transformable customizations and applications, our software will suggest training activities for your team to undergo before the transformation takes place. Source material, recorded conference sessions and blog posts make sure you’re fully prepared, helping the project run as smoothly as possible.

Plan & Track

The final preparatory step, our software will create a complete view of every element to your transformation project so you can plan and track them all. Often with a migration, it helps to only migrate what you need. You can decide what goes and what stays behind.


We’re with you every remaining step of the way, guiding you through the actual transformation of your customizations and applications. It automatically provides you with the transformed code in the desired development model: JavaScript REST, PowerShell, PnP, SharePoint Framework and many more.

Over to you

Whether fully migrating or partially migrating to SharePoint Online, organizations are using Rencore  Migration Assessments as a starting point to modernize and optimize their collaboration platform approach. They have found that development time, technical support cases have reduced significantly.

Rencore Assesssments combine powerful insights through award-winning software and comprehensive advice delivered by experts. We provide best-in-class analyses, reports, and action plans for you to stay in control of your SharePoint and Office 365. We recommend you check out our Migration Assessment offering as the first port of call.

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Erwin van Hunen

Erwin is a Microsoft MVP, Microsoft Certified Master, and Microsoft Certified Solutions Master and works at Rencore. He is a Principal Technology Advisor focusing on application modernization to help customers successfully migrate from on-premises solutions and traditional solution packages to the modern development techniques in SharePoint. Erwin is a core member of the SharePoint Patterns and Practices team helping developers worldwide with code samples, scenarios, solutions, and guidance to successfully implement customizations for SharePoint and SharePoint Online. Erwin is speaking regularly at tech conferences around the world.