Tasks, milestones & dependencies

This page covers the structure and scheduling elements of the chart: the task hierarchy and how it's ordered, milestone markers, and dependency arrows between tasks.

The task hierarchy

The hierarchy comes from the Category field — each column is one level of nesting (see Fields → Category). This section covers how it's displayed and controlled.

Expand & collapse

Every parent row has a toggle to expand or collapse its children. The state is remembered — if you collapse a project in editing and save, viewers see it collapsed. Collapse and expand state is also captured by Power BI bookmarks, so you can build guided views.

Row numbers (WBS)

Format → Project hierarchy → Row numbers

Turns on a Work Breakdown Structure number column to the left of the task list (e.g. 1, 1.1, 1.2, 2). Off by default.

Color swatches

Format → Project hierarchy → Show color swatches

Shows a small color chip next to each project/parent name in the task list, matching its bar color. On by default.

Completion checkmarks

Format → Project hierarchy → Show completion checkmarks

Shows a green checkmark next to tasks that are 100% complete (requires a Progress bar field). On by default.

Milestones

Milestones are key dates plotted as markers on a task's row. Add one to five date columns to the Task milestones field (see Fields → Task milestones).

Choose a symbol per milestone

Format → Milestones → Symbols

Each milestone column gets its own symbol picker. Available symbols: Circle · Diamond · Square · Triangle · Star. This lets you distinguish, say, a "Review" milestone (diamond) from a "Go-live" milestone (star).

Zero-duration tasks

A task whose start and end dates are the same has nothing to draw as a bar. By default the visual draws it as a milestone marker instead, so single-day events in your task table appear as milestones without needing a separate Task milestones column.

Format → Milestones → Options

Setting	What it does	Default
Zero-duration tasks as milestones	Draws same-day tasks as a marker rather than a bar.	On
Task milestone symbol	The shape used for those tasks.	Diamond

Turn the toggle off if you'd rather these tasks stay as (very short) bars.

Marker options

Format → Milestones → Options

Setting	What it does	Default
Hide markers outside bars	Hides milestone markers that fall outside their task's start–end range.	Off
Marker size (%)	Size of markers as a percentage of task bar height (10–80%).	30%

Dependencies

Dependency arrows show that one task can't start until another finishes. They require two fields: Task ID and Predecessor ID.

Set it up

1. Add a unique identifier column to Task ID (e.g. 1, 2, 3).
2. Add the predecessor column to Predecessor ID. Each value lists the IDs this task depends on, separated by commas or semicolons.

Task ID	Task	Predecessor ID
1	Discovery
2	Design	1
3	Build	2
4	Launch	2;3

Here "Launch" depends on both "Design" (2) and "Build" (3), so it receives an arrow from each.

Style the arrows

Format → Dependency lines

Setting	What it does	Default
Show	Turns dependency arrows on or off.	On
Color	Arrow color.	#323338 (dark gray)
Style	Solid, Dashed, or Dotted.	Solid
Width	Arrow line thickness, 1–5 px.	1 px

caution

Arrows only appear when both Task ID and Predecessor ID are populated and the IDs match. If an arrow is missing, check that the predecessor value exactly matches an existing Task ID and that IDs are unique.

Related

• Progress, colors, labels → Progress, colors & appearance
• Every setting in one place → Formatting reference