How to Open an XER File That Contains Multiple Projects

By XER Reader Team • September 13, 2026 • 4 min read
How to Open an XER File That Contains Multiple Projects

A single XER file can hold several projects. When one does, XER Reader shows the Project Options dialog before loading anything, and each project is handled separately.

Project Options dialog in XER Reader listing three projects from a multi project XER file with their activity counts and an Action for each
Every project in the file is listed with its activity count and an Action.

What the dialog shows

ColumnContains
NameThe project name from the file. It can be edited here before import
Activity CountHow many activities the project holds
ActionWhat to do with this project

Nothing is loaded until Apply. Cancel abandons the file entirely.

The four actions

Action dropdown open in the Project Options dialog showing Open, Import only, Open links only, and Do not import
Each project takes its own action, set independently of the others.
ActionResult
OpenImports the project and opens it. All of its activities are loaded and displayed
Import onlyImports the project into the Available Projects list without opening it. It can later be assigned as a baseline or used to replace the open project
Open (links only)Opens the project with only the activities that are linked to another imported project
Do not importLeaves the project out. Its activities and its links to the other projects are discarded

The dialog carries an information button that states the same four definitions.

Information panel in the Project Options dialog explaining Open, Import only, Open links only and Do not import
The information button in the dialog explains each action.

Open (links only)

This is the action to reach for when a neighbouring project matters only because your schedule depends on it.

A large programme is often split across several projects with interface milestones tying them together. Opening all of them in full buries your own activities among thousands you do not own. Excluding them entirely discards the relationships, and the dates that depend on them stop making sense.

Open (links only) is the middle option. The project is opened, but only the activities that are linked to another imported project are brought in. The interface points remain visible and the driving logic across the boundary is preserved, without the rest of that project's detail.

Project Options dialog with a project set to Open links only, its Activity Count showing six of six
With Open (links only) selected, the Activity Count shows how many activities are linked, out of the project total.

The Activity Count column changes format for a links only project, showing the linked count out of the total, for example 6 of 6. Check this number before applying. A project reporting 4 of 900 contributes four interface activities, while one reporting 0 has no links to the projects you are importing and will contribute nothing.

Choosing an action per project

The actions are set independently, so a typical multi project file is handled as a mixture.

ProjectUsual actionWhy
The one you are reviewingOpenYou need all of its detail
A neighbouring project you interface withOpen (links only)The interface activities matter, the rest does not
A previous update of the same projectImport onlyAssign it as a baseline afterwards
Anything unrelated in the fileDo not importKeeps the schedule to what you are working on

Import only and the Available Projects list

A project imported without being opened goes to the Available Projects list in Tools then Manage Baseline. That list holds every imported project, not only the open ones. From there a project can be assigned as a baseline, or dragged into the main project slot to replace what is open.

This is the route for comparing two updates of the same programme that arrive in one file. Open the current one, import the earlier one, then assign it as the baseline.

Renaming before import

The Name column is editable in this dialog. Where a file carries several projects with similar names, renaming them here is easier than working out afterwards which is which, because the name is what identifies a project in the baseline list and in the export project selector.

What happens to cross project links

Relationships between projects survive only where both ends are imported. Setting a project to Do not import discards its links to everything else in the file, so an activity that was driven across the boundary loses that predecessor. If a date looks wrong after import, and the activity has no driving predecessor, check whether the project at the other end of that link was excluded.

After import

Exporting from a multi project file asks which project to write, through Export Project in the Export dialog. See Export schedule data.

If activities you expect are missing after opening a multi project file, the import actions are worth checking before the filters. A project set to Do not import, or to Open (links only), is a more likely explanation than a WBS or column filter you do not remember applying.

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