Auto-Scheduling

Auto-scheduling is a PRO feature. See licensing and trial info.

Auto-scheduling lets the Gantt automatically move tasks forward whenever an upstream task changes. When enabled, any task linked by a Finish-to-Start dependency is rescheduled so it starts no earlier than its predecessor ends. This removes the need to manually adjust dates throughout a dependency chain.

The `schedule` Prop

Pass a schedule object to the <Gantt> component to configure scheduling behaviour.

interface IScheduleConfig {
  type?: "forward";  // scheduling direction — only forward mode is supported
  auto?: boolean;    // when true, reschedules on every data change automatically
}

Property	Type	Default	Description
`type`	`"forward"`	—	Scheduling algorithm. Only forward scheduling is available.
`auto`	`boolean`	`false`	When `true`, tasks are rescheduled automatically on every change.

The `summary` Prop

The summary prop controls automated behaviour for summary (parent) tasks.

interface ISummaryConfig {
  autoProgress?: boolean;  // auto-calculate summary task progress from children
  autoConvert?: boolean;   // auto-convert a task to a summary when children are added
}

Property	Type	Description
`autoProgress`	`boolean`	Recalculates the `progress` of summary tasks based on child task progress.
`autoConvert`	`boolean`	Automatically changes a task’s `type` to `"summary"` when child tasks are added.

Forward Scheduling Mode

In forward scheduling mode (type: "forward"), the engine starts from the project start date and propagates task dates forward along the dependency chain:

Tasks with no predecessors are placed at the projectStart date.
Each Finish-to-Start (e2s) link causes the target task to start on or after the source task’s end date.
If auto: true, this recalculation runs on every task edit, drag, or resize.

Links with a lag value are respected — the target task starts lag working days after the source ends (when a calendar is configured).

Basic Example

The demo below enables auto-scheduling with a fixed project start date. Moving or resizing any task propagates the change through the dependency chain automatically.

<script>
  import { getData } from "../data";
  import { Gantt, Editor, ContextMenu } from "@svar-ui/svelte-gantt";

  let api = $state();
  let projectStart = $state(new Date(2026, 3, 2));
  const data = getData();
</script>

<Editor {api} />
<ContextMenu {api}>
  <Gantt
    bind:this={api}
    tasks={data.tasks}
    links={data.links}
    scales={data.scales}
    schedule={{ auto: true }}
    {projectStart}
    projectEnd={new Date(2026, 5, 2)}
  />
</ContextMenu>

How Finish-to-Start Scheduling Works

When schedule.auto is true, every e2s (end-to-start) link is evaluated after each change:

The source task finishes at a calculated date.
The target task start is pushed to match or exceed the source end date.
The target’s end date shifts by the same offset, preserving duration.
The cascade continues down the dependency chain recursively.

Combine schedule with the Calendar prop so that scheduling respects working days and hours. Durations are measured in working time when a calendar is active.

Controlling Project Bounds

Use projectStart and projectEnd props to constrain the scheduling window:

<Gantt
  tasks={data.tasks}
  links={data.links}
  scales={data.scales}
  schedule={{ auto: true }}
  projectStart={new Date(2026, 3, 2)}
  projectEnd={new Date(2026, 5, 2)}
/>

Tasks will not be scheduled before projectStart. The projectEnd date is used by the Critical Path engine to identify late tasks.

Get Started

Configuration

Guides

PRO Features

Migration

The `schedule` Prop

The `summary` Prop

Forward Scheduling Mode

Basic Example

How Finish-to-Start Scheduling Works

Controlling Project Bounds

​The schedule Prop

​The summary Prop

​Forward Scheduling Mode

​Basic Example

​How Finish-to-Start Scheduling Works

​Controlling Project Bounds

The `schedule` Prop

The `summary` Prop

Forward Scheduling Mode

Basic Example

How Finish-to-Start Scheduling Works

Controlling Project Bounds