Recent announcements from Microsoft about the future compatibility of Office applications with its Office 365 platform have further highlighted the importance of staying up to date client side. Whilst for some, the use of online applications only may be a viable option, most organisations still rely on the use of locally installed Office applications either via O365 or it’s more-traditional, MSI-based relation.

The changes announced are simple enough as a one liner; as of 13th October 2020, you must be using Office 365 ProPlus OR Office perpetual in mainstream support to connect to O365.

We’ll come to the supportability of Office 365 ProPlus shortly, but it’s worth highlighting the end of support dates for recent/current versions of Office:

VersionMainstream EndExtended End
Office 201013th October 201513th October 2020
Office 201310th April 2018 11th April 2023
Office 201613th October 202014th October 2025

Using the above information, we can see that officially Office 2010 is already out of mainstream support, 2013 has less than a year remaining and by the time this new change comes into effect – 2016 will also no longer be supported. So, what do these dates mean when connecting to O365?Using the above information, we can see that officially Office 2010 is already out of mainstream support, 2013 has less than a year remaining and by the time this new change comes into effect – 2016 will also no longer be supported. So, what do these dates mean when connecting to O365?

Key wordings from Microsoft:

If you use older browsers and versions of Office that are not in mainstream support:

  • Microsoft won’t deliberately prevent you from connecting to the service, but the quality of your Office 365 experience will diminish over time
  • Microsoft won’t provide code fixes to resolve non-security related problems

Office 365 doesn’t support interoperability with any software that isn’t supported by its manufacturer.

This largely discounts the use of Office 2010 as a viable option when using O365 services but we know that theoretically, it will still be useable. Even the most recent technically forced change to Office versions supported in O365 (related to email) still suggests that 2010 can be used:

RPC over HTTP deprecated in Office 365 on October 31, 2017

One notable issue with Office 2010 however is the lack of support for Modern Authentication (ADAL authentication) when compared to 2013 or 2016 clients. Whilst we won’t go into detail on that in this blog, it’s certainly worth ensuring the version of Office in use supports this technology, particularly where single sign-on infrastructure such as ADFS is due to be deployed or is desirable.

Office 2013 updated authentication enabling multi-factor authentication

So, after discounting Office 2010 this realistically leaves two viable options: Office 2013 or Office 2016. Both support all new and modern features of Office 365 such as Groups and Teams, both have near identical user interfaces and both have largely similar supportability for 3rd party plugins, applications and operating systems.

Whilst 2013 has an effective end of support date next year, it is likely to still be marginally as viable an option as 2010 is today (at the very least) yet it still faces a hard-stop in 2020 along with Office 2016.

What are the options?

Deploying any version of Office via an MSI-based installer that is available today is going to give at most three years of use with O365, ending with an upgrade to Office 2019 (?) or finally succumbing to Office 365 ProPlus anyway. For organisations who must install a new version of Office to complete a move to O365, it surely makes little sense now to take on two large upgrades over the next few years when one will do the job.

By deploying O365 ProPlus, organisations are effectively future proofed and will have a gradual transition to the next version of Office thanks to the update model found in ProPlus. Sounds like a no brainer?

Why would an organisation not deploy ProPlus?

This may be for several reasons. By and large, the MSI-based installer found in perpetual Office versions is the tried and tested default for many. It’s a model that is well understood and provides longer term stability than ProPlus, where updates must be installed on a regular basis (see below).

It may also be due to application compatibility, licensing or simply that only recently did an Office upgrade already take place and appetite for another does not exist.

Whatever the case, ProPlus does present its own challenges. For starters, as mentioned above updates are required on a much more regular basis than perpetual Office versions. Microsoft has been tweaking the release model regularly over the last year or so and will again in September, moving ProPlus updates to be either monthly or six-monthly depending on the organisations choice.

Other challenges (or opportunities) include changes to licensing, authentication and indeed the installation method itself. These reasons typically count against ProPlus when comparing against the MSI-based equivalent.

A final headline difference is the fact that specific releases in Office 365 ProPlus are only supported for a maximum of 18 months (again, as of Sep/2017). The good news is that organisations who have an up-to-date deployment of Microsoft System Centre Configuration Manager (SCCM) can easily manage and control the specific versions of ProPlus installed and gradually deploy newer versions to confirm compatibility with any critical LOB applications. Without this, clients will simply update via the web automatically once updates become available.

The options

In closing, organisations looking to go to the cloud have two choices when it comes to Office:

Option 1, which is to deploy the perpetual/MSI-based Office in the knowledge that they will require another large upgrade before the end of 2020, even if installing Office 2016

Option 2, which is to deploy Office 365 ProPlus and select a suitable update method to receive gradual updates to ensure ongoing support beyond 2020.

For most, Option 2 is the more viable option but for a host of reasons, some will still be pursing Option 1. Whichever option is decided, the days of being able to simply install and only patch security updates for Office are truly long gone when moving to Office 365.

How Silversands can help?

Through a deep understanding of both the MSI-based version of Office and Office 365 ProPlus, Silversands can help identify which product fit’s each organisation best. Once a solution has been selected, our experience of migrating customers has helped develop standardised approaches that can be further tailored to any environment to ensure a smooth transition.

Please use the attached form if you require any more information on this blog or to find out how we can help.

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