> ## Documentation Index
> Fetch the complete documentation index at: https://learn.nextedy.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Perform What-If Analysis Without Saving

> Use Nextedy GANTT edit mode to explore schedule changes interactively without committing them to Polarion, allowing you to evaluate different scheduling scenarios before deciding to save.

export const LastReviewed = ({date}) => {
  if (!date) return null;
  const formatted = new Date(`${date}T00:00:00Z`).toLocaleDateString("en-US", {
    year: "numeric",
    month: "long",
    day: "numeric",
    timeZone: "UTC"
  });
  return <p className="mt-10 text-sm text-gray-400 dark:text-zinc-500 not-prose">
      Last reviewed on {formatted}
    </p>;
};

## How It Works

The Gantt chart operates in a two-phase editing model: you make changes in edit mode, and those changes only persist to Polarion when you explicitly click **Save**. Until you save, all modifications are local to your browser session. This makes the Gantt a natural tool for what-if analysis.

<Frame>
  <img src="https://mintcdn.com/none-17b4493f/umKaPvHwUHw-ZQFM/gantt/diagrams/guides/scheduling/what-if-analysis/diagram-1.svg?fit=max&auto=format&n=umKaPvHwUHw-ZQFM&q=85&s=667e6acf816d30951430a84db9c3fd88" alt="diagram" style={{ maxWidth: "780px", width: "100%" }} width="780" height="200" data-path="gantt/diagrams/guides/scheduling/what-if-analysis/diagram-1.svg" />
</Frame>

<Steps>
  <Step title="Enter Edit Mode">
    Click the **Edit** button in the Gantt toolbar. Task bars become draggable, and the lightbox becomes available for field editing.

    <Note title="Always-edit mode">
      If your Gantt is configured with `alwaysedit` mode, the chart is always editable and there is no Edit button. In this case, unsaved changes still behave the same way -- they are not persisted until you click Save.
    </Note>
  </Step>

  <Step title="Experiment with Schedule Changes">
    With the Gantt in edit mode, you can perform any combination of the following:

    * **Drag task bars** left or right to change start dates
    * **Resize task bars** to change duration
    * **Edit dates in the lightbox** for precise adjustments
    * **Create or remove dependency links** to evaluate cascading effects
    * **Move parent tasks** to shift entire work breakdown branches

    If auto-scheduling is enabled, moving one task automatically recalculates the dates of dependent successors, giving you immediate feedback on the downstream impact of your change.
  </Step>

  <Step title="Evaluate the Impact">
    Review the schedule after your changes. Key indicators to watch:

    | Indicator         | What to Look For                                                            |
    | ----------------- | --------------------------------------------------------------------------- |
    | Task bar colors   | Red or orange bars indicate overdue or delayed items                        |
    | Dependency arrows | Red dotted lines indicate violated dependency constraints                   |
    | Resource view     | Overallocated resources appear highlighted in the resource view             |
    | Critical path     | If enabled, critical path highlighting shows which tasks drive the end date |
    | Range conflicts   | Parent tasks with out-of-range children are visually flagged                |
  </Step>

  <Step title="Save or Discard">
    **To save your changes:** Click the **Save** button in the Gantt toolbar. All modifications are persisted to Polarion work items.

    **To discard your changes:** Reload the page in your browser. The Gantt reloads the original data from Polarion, reverting all unsaved changes.

    <Warning title="No built-in conflict detection for concurrent editors">
      The Gantt uses a last-save-wins model. If another user saves changes to the same work items while you are in edit mode, your save will overwrite their changes. Coordinate with your team when performing what-if analysis on shared schedules.
    </Warning>

    <Tip title="Use baselines for comparison">
      Before starting your what-if analysis, save a baseline snapshot. This lets you compare your experimental schedule against the original plan visually, even after saving changes. See [Compare Schedule with Baselines](/gantt/guides/visualization/baselines-comparison).
    </Tip>
  </Step>
</Steps>

## Verification

You should now see:

* Task bars responding to drag and resize in edit mode without any server communication
* Dependency links recalculating successor dates in real-time when auto-scheduling is enabled
* All changes reverting cleanly when you reload the page without saving

## See Also

* [Configure Auto-Scheduling](/gantt/guides/scheduling/configure-auto-scheduling)
* [Compare Schedule with Baselines](/gantt/guides/visualization/baselines-comparison)
* [Handle Unsaved Changes and Session Timeout](/gantt/guides/editing/unsaved-changes)
* [Use Undo and Redo](/gantt/guides/editing/undo-redo)

<LastReviewed date="2026-07-02" />