What is an XER file?
An XER file is the file Oracle Primavera P6 produces when a project is exported in its native exchange format. It is the file contractors, consultants and employers pass around when a programme has to be submitted, reviewed or moved between P6 databases. Contract programme submissions on many Gulf projects are requested in XER form precisely because it carries the full schedule logic, not just a picture of the bars.
Structurally, an XER is a plain-text file with tab-separated values. Data is grouped into tables, and each table has a header row of field names followed by rows of records. Tables you will typically find include PROJECT (project-level data), PROJWBS (the work breakdown structure), TASK (the activities), TASKPRED (the relationships between activities), CALENDAR (working calendars) and RSRC (resources). Records point to each other with internal ID fields, which is why the file is readable by software but awkward for people.
How is XER different from XML, XLSX and PDF exports?
| Format | What it is | Best used for |
|---|---|---|
| XER | Tab-delimited text, P6's native exchange format | Moving a full schedule between P6 databases or into tools that read P6 data |
| XML | Structured XML export from P6 | Integrations and tools that prefer XML |
| XLSX / XLS | Spreadsheet of selected columns | Reviewing the activity table, filtering, sharing with people who do not use P6 |
| Printed layout of a Gantt or report | Reading and approvals, where nobody needs to edit |
The key difference is that XER and XML retain logic (relationships, calendars, constraints) while a spreadsheet or PDF is a snapshot of whatever columns were on screen. If you need to re-calculate or analyse the programme, you need XER or XML. If you only need to read it, a PDF may be enough, but you will not be able to check the logic behind it.
How do I open an XER file in Primavera P6?
If you have P6 Professional, use the import function in the File menu and choose the XER file. You will be asked whether to create a new project or update an existing one, and P6 will check the file against your database. Menu labels and wizard steps vary slightly between P6 versions, but the process is: import, choose the file type, map or accept the defaults, then open the resulting project.
Be careful when importing into a live database. An import can bring in calendars, activity codes and resources that clash with your own. Many teams import into a sandbox database or a separate test project first.
How do I open an XER file without a P6 licence?
You have three practical options.
- Use a viewer. If you only need to read the programme, a viewer is the quickest route. A free browser-based P6 viewer lets you open an XER file in the browser to see a Gantt, the WBS and the critical path. See the tool page for exactly what it supports.
- Ask the scheduler for another export. An XLSX export of the activity table, or a PDF of the Gantt with the critical activities highlighted, is often enough for a review meeting. We cover how in how to export a P6 schedule to Excel or PDF.
- Inspect it as text. Open the file in a text editor to confirm which project it contains, which version of P6 wrote it and which tables are present. This is a diagnostic step, not a way to read a programme.
If you manage project documents in Arkan, the Schedule module accepts Primavera files in XER or XML format, shows activities in grid and Gantt views and lets you compare schedule versions. The file must be under 50 MB, per the module's user guide.
What can go wrong when you share or open an XER?
- Version mismatch. A file written by a newer P6 release may not import cleanly into an older one. If an import fails, ask the sender which version wrote the file and whether they can export for an older release. Check this against your own P6 version rather than assuming.
- Missing context. An XER holds activities and logic, not the narrative. Without the programme notes, baselines and calendars that explain the assumptions, a reader may misjudge the critical path.
- Several projects in one file. An export can contain more than one project, or a baseline alongside the current schedule. Confirm which one you are looking at before drawing conclusions.
- Data date confusion. The data date sets what is treated as progressed and what is still forecast. Check it first; our guide to reading a P6 schedule explains why.
Is it safe to share an XER file?
An XER can include the full programme logic, resource and cost-related fields if they were populated, user names and notes. Before sending one to a third party, export only the project that was asked for, check that unneeded baselines and other projects are not included, and use your normal controlled transmittal route so there is a record of what was issued and when. Keep the file under document control rather than circulating copies by chat or personal email.
When is an XER file not enough?
An XER tells you what the plan says. It does not tell you whether site progress matches it. To compare programme against reality you need progress updates, daily reports and inspection records tied to the same activities. If you are replacing spreadsheet-based tracking, book a demo to see how Arkan connects the uploaded schedule to site records.