Is it possible to roll up multiple timelines in a project summary

Question

I want to create several project sites and then have a top level project site with a project summary that rolls up the tasks and events from all sub projects into a single project summary. Is it possible to customize a project summary to show more than one timeline?

Answer 1

I have found that it is not possible to roll up multiple task list timelines into a single project summary. However, I've found that a great alternative is to just create a page (or use an existing page) and add multiple Timeline web parts that are each connected to your relevant task list. This displays separate timelines, but for me that works well enough. I haven't tried doing this with project summary web part, but I will do so and update my answer if it works.

Reference this solution for the basic steps of how to add a timeline web part to a page and link it to the source task list. The basic gist of it is to:

1. Edit the page.
2. Insert a Web Part and choose the Timeline web part.
3. Edit the web part properties.
4. Enter the URL of the site/sub-site that the task list is under (if different from the site where the page is).
5. Select the task list and click OK.
6. Save your edits to the page.

EDIT/UPDATE

You CAN modify a Project Summary webpart to show items from multiple task lists or calendars in the project site, but only under Late and Upcoming. You cannot have multiple timelines from multiple task lists in one Project Summary.