Convert GAN to MPP

A .gan project needs conversion when a client or team uses Microsoft Project and requires an editable .mpp schedule. The dependable workflow is to export the plan from GanttProject as Microsoft Project XML, open that XML in Microsoft Project, and save it as .mpp.

What the GAN format contains

.gan is GanttProject's XML-based project format. GanttProject users use it to store task hierarchies, dates, durations, milestones, dependencies, resources, assignments, and project settings in a free desktop scheduling application.

A GAN file is not an MPP file, and changing the extension does not convert it. It must be opened by GanttProject or processed by software that understands GanttProject's XML structure.

What the MPP format provides

.mpp is Microsoft Project's native project format. It is designed for editable schedules containing tasks, relationships, resources, calendars, costs, constraints, and Microsoft Project-specific scheduling data.

MPP is the practical delivery format when recipients need to edit the plan in Microsoft Project. It is not an open interchange format, and compatibility depends on the Microsoft Project version and the features used in the source plan.

Convert GAN with GanttProject and Microsoft Project

1. Install the current desktop release of GanttProject from ganttproject.biz. Make a backup of the original .gan file.
2. Open the GAN file in GanttProject and check task dates, durations, dependencies, resources, assignments, milestones, and calendars before exporting.
3. Use the export command labeled File → Export or Project → Export, depending on the GanttProject release, and select Microsoft Project XML. Save the resulting file with an .xml extension.
4. In the desktop version of Microsoft Project, choose File → Open → Browse, select the XML file, and import it as a new project when prompted.
5. Compare the imported schedule with the GAN version, then use File → Save As and select Microsoft Project (*.mpp).
6. Reopen the saved MPP file and verify task links, calendars, resource assignments, constraints, costs, and the critical path before sharing it.

The XML file is an intermediate exchange file, not the requested final format. GanttProject does not provide a native, general-purpose MPP export; its supported route is Microsoft Project XML followed by saving in Microsoft Project.

Options when Microsoft Project is unavailable

ProjectLibre and other project-planning applications may open Microsoft Project XML or some MPP files, but their ability to write a fully compatible native .mpp file varies. Use them for inspection or further editing only after confirming that the recipient's Microsoft Project version accepts the output.

There is no consistently reliable mainstream online service that accepts GanttProject .gan files and produces native .mpp files. Online converters that support generic XML usually cannot interpret GanttProject's project schema or recreate Microsoft Project scheduling behavior. Avoid uploading confidential schedules, personnel data, or cost information to unverified conversion sites.

Compatibility and data-loss limits

Microsoft Project XML can transfer common tasks, hierarchy, dates, durations, links, milestones, resources, and assignments, but it cannot guarantee a complete one-to-one translation. Custom fields, advanced constraints, baselines, earned-value data, resource leveling results, detailed calendars, styling, and application-specific settings may be omitted, approximated, or recalculated.

After conversion, compare the number of tasks and resources, summary-task rollups, dependency types, working time, fixed-date constraints, costs, and project finish date. If the MPP will drive contractual dates or resource commitments, keep the original GAN and exported XML as audit copies and obtain approval from the schedule owner after validation.