Request input on External Sharing design - subsites and SharePoint groups versus O365 Groups

[Julie Sanders]

I'm looking for comments and feedback on an external collaboration solution. If anyone has implemented a similar solution, I would love to hear feedback on your experience - what worked well and what didn't.

Scenario:

• 100 ongoing client consulting projects - lots of tracking, document creation, etc. Projects have 4-10 consultants and may last from 6 months to 5 years. Most of this content should NOT be shared with a client.
• Some projects need a client collaboration solution. Anything from submitting status reports to collaborating on documents to a 'drop box' type experience.
• We have a classic SharePoint experience, even though we are on Office 365.
• We are using Office 365 Security Groups to control internal employee permissions on SharePoint.
• Support staff is minimal. Anticipate training individual team members to manage the sites, permissions and invite the external users.

Proposed solution:

• Separate site collection (from main Intranet) for "Projects" enabled for external sharing.
• 1 site per project - not externally shared. There will be multiple customized templates to choose from based on the type of project.
• Project team may request a subsite to collaborate externally. This site will reside under their project site.
• Use SharePoint Groups to invite and manage the external users to the subsite. Note, this would be a separate permissions model from how employee permissions are handled. (We are using O365 Security Groups for employees as mentioned above.)

Why this set up

• Initial thought was to share 'parts' of the main project site with the client. I'm concerned about the amount of manipulation and ongoing support needed to customize permissions of different libraries and apps (for 100 sites). The risk (due to human error) of a client seeing unauthorized content is higher with this model. However, the separate subsite strategy requires duplicate file storage, but the Copy To feature or a basic workflow, could keep this manageable.
• Another option was to create an Office 365 Group for the external sharing piece instead of a subsite. The process to add new and manage users is more user friendly, but the users find the sites and navigation (with conversations) confusing compared to the classic experience. Plus we have the requirement for site templates with predefined libraries, apps, and web parts.

Your comments are greatly appreciated.

[#2]

Your close with the thinking however I wouldn't use subsites for the external users. Your best bet is to use communication sites. These are similar to classic sites, but are MUCH easier for people to create content and manage. You can quickly show users to keep control of these sites and they are great for this purpose. External sharing will be similar to classic sites as well.

I would also highly consider Teams for this scenario, you get easy user management and complete collaboration platform to use for files / conversations etc. Have internal and External Teams. The only issue with Teams you'll run into is if you have clients that use Office 365 but have Teams disabled. In that case you have to invite personal Microsoft Accounts to join. That's the biggest current caviot when using Teams for active external use.

[#3]

Is the collaboration with external users limited to file sharing or do you need also communication?

[#4]

Primarily file sharing. At this point they are not ready to use chat-type communications tools with their clients. And the company internally uses Slack and they aren't interested in switching to Teams.

[#5]

A couple of comments:

1. It's not clear to me what you mean by "We are using Office 365 Groups to control internal employee permissions on SharePoint". So you have not classic team sites, as you stated, but modern team sites (i.e. connected with Office 365 Groups)?
2. In any case, subsites are not the current trend, hence I would avoid them. Moreover, if I understand well, you don't need pages (i.e. an additional team site), but only file storage, am I correct? If this is the case, you could create one additional library (or even a simple additional folder) in each (modern?) team site and share with externals just that library/folder.

Just my two cents...

[#6]

I've got an almost identical dilemma on my hands.  On top of everything the OP posted, one external collaborator could be a part of many different projects.  I obviously don't mean to hijack, but I'm listening intently on what the community thinks the best way to tackle this problem is.