Project Online offers two security management options for controlling the kind of access that users have to sites and projects:
SharePointPermission Mode With this option selected, a special set of SharePoint security groups are created in sites associated with Project Online. These groups are used to grant users varying levels of access to projects and Project Online functionality.
Tip: To learn more about the permissions included in the security groups used with SharePoint Permission Mode, see SharePoint Permissions Mode default permissions for Project Server 2013 SharePoint groups. While this article is written with Project Server 2013 in mind, the information also applies to Project Online.
Project Permission Mode With this option selected, Project Online provides a set of customizable security groups and other functionality that is distinct from SharePoint groups.
Project Online uses SharePoint Permission Mode, by default. This mode is more streamlined, enabling you to implement security quickly and consistently across SharePoint Online and Project Online. However, there may be situations where it makes more sense to use Project Permission Mode. For example, if you think your organization could benefit from using delegation, you’ll need to use Project Permission Mode. This mode offers greater control, because you can customize and change individual permissions for each security group.
Site collection administrators have administrative permissions to the Project Online site. These permissions allow the site collection administrator to bypass any Project Online security permissions set in SharePointPermission Mode or Project Permission Mode. This way, someone always has access to Project Online. What should I do if my Project Online administrator gets locked out?
Warning: Switching between SharePoint Permission Mode and Project Permission Mode deletes all security-related settings. If you switch from SharePoint Permission Mode to Project Permission Mode, you have to manually configure your security permissions structure in Project Online. Switching from Project Permission Mode back to SharePoint Permission Mode deletes your security permissions information from Project Online.
To change between permission modes:
Sign in to Office 365 with your admin account and go to the SharePoint admin center.
Hover over the URL for the Project Web App site collection that you want to change, and then select the check box that appears to the left of the URL.
Select Project Web App > Settings on the ribbon.
Choose the permission mode you want to use for your Project Web App site: SharePoint Permission Mode or Project Permission Mode.