## Overview

The Multi Gantt Chart widget displays any number of schedules at the same time, which are pre-selected in the widget configuration. It aggregates multiple schedules into a unified timeline visualization, enabling stakeholders to see consolidated project timelines at a glance.

**Use when**:
- Building project dashboards that need to show all associated schedules
- Creating portfolio-level views across multiple projects or programs
- Providing executive summaries of timeline status across organizational units

**Alternatives**:
- **Single Gantt Link**: When you only need to preview a single schedule
- **Schedule Tree Table**: When tabular WBS data is more appropriate than timeline visualization

## Use Cases

### Project Timeline Dashboard
A project manager needs visibility into all schedules related to their project. The Multi-Gantt consolidates schedules that are either direct children of the project or linked through additional associations, presenting them in one interactive timeline.

### Portfolio Overview
Program managers and executives need to monitor multiple projects simultaneously. The widget can aggregate schedules across a filtered set of projects, enabling cross-project timeline comparison and dependency awareness.

### Status Reporting Views
For stakeholder communication, a read-only aggregated view provides timeline context without the risk of accidental modifications. This supports status meetings and reporting workflows where visibility matters more than editability.

## Behavior and Capabilities

### Schedule Aggregation
The widget discovers schedules through search-based filtering. This allows flexible aggregation strategies:
- Schedules directly owned by a project
- Schedules linked through reference attributes
- Schedules matching arbitrary search criteria

The dual-path discovery pattern (parent reference OR link reference) is common, ensuring schedules are found regardless of how they relate to the containing page.

### Expansion Control
Users can control how much detail appears initially. The widget supports starting fully expanded (all tasks visible), partially expanded (schedule headers visible, tasks hidden), or fully collapsed (compact summary). This lets designers balance information density against cognitive load.

### Read-Only Mode
The widget can operate in read-only mode, preventing inline edits while preserving visualization and navigation capabilities. This is essential for aggregation views where editing should happen at the individual schedule level.

### Cross-Schedule Dependencies
Dependency relationships between schedules can be shown or hidden. Showing dependencies reveals cross-schedule coordination requirements; hiding them reduces visual complexity for overview purposes.

### Sorting
Schedules can be ordered by various attributes, most commonly by name for intuitive alphabetical navigation.

## Design Considerations

### Information Density Trade-offs
Aggregating many schedules creates information overload risk. Design decisions to mitigate this:
- Start collapsed to give users control over what they expand
- Hide cross-links in overview contexts to reduce visual noise
- Use read-only mode to signal "viewing" rather than "editing" intent

### Editing Context
Multi-Gantt is fundamentally an aggregation view. While it can support editing, the recommended pattern is to use it for overview and navigation, directing users to individual schedule views for detailed editing. This prevents confusion about which schedule they're modifying.

### Performance Awareness
Large aggregations (many schedules with many tasks) can impact performance. For portfolio-level views spanning many projects, consider filtering strategies or pagination approaches to keep the visualization responsive.

### Search Filter Design
The search mechanism is powerful but requires careful filter construction. The common pattern of searching for schedules via multiple reference paths (parent AND link) provides flexibility but adds complexity. Test filter logic thoroughly before deployment.

## Related Widgets

### Single Gantt Link
**Single Gantt Link** provides a lightweight preview of a single schedule. Use it when embedding schedule context without the full multi-schedule aggregation overhead. It's a simpler choice when only one schedule is relevant.

### Schedule Tree Table
**Schedule Tree Table** presents WBS (Work Breakdown Structure) data in tabular form rather than timeline form. Choose it when users need to see task details, assignments, or other attributes that don't fit well in a Gantt visualization.

### Complementary Pattern
A common layout pattern places Multi-Gantt on a dedicated "Timeline" or "Gantt" tab, keeping the main page cleaner while providing focused timeline access. This separates timeline visualization from other project information widgets.