Dependencies

Scheduler can show that one task follows another, and draw the relationship as an arrow across the timeline. What makes this more than a drawing is where the relationship lives: a dependency on the board is a Polarion work item link. Create a dependency by clicking the Add Link handle on two cards, and the link appears on the work items themselves — visible in the Links section of each work item, queryable, exportable, and part of the project’s history like any other link. Delete the link in Polarion and the arrow disappears from the board. There is no separate store of board-only relationships. That single design decision explains most of how dependencies behave, including why they need configuration before they can be used at all.

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Dependency Roles Come First

Polarion does not have one universal “depends on” relationship — it has a configurable set of work item link roles per project, and each role declares which work item types it may connect. Scheduler cannot guess which of those roles means “this task follows that one”, so nothing about dependencies works until you tell it. You do that with the Dependency Roles parameter, in the widget’s Work Items parameter section. It offers the link roles configured in the project, and accepts more than one. Until at least one role is selected:

• Hovering a task card does not reveal the Add Link handle, so links cannot be created from the board.
• The Show Dependencies toolbar button is not displayed, so there is no overlay to turn on.

A board with no Dependency Roles configured is simply a board without dependencies — not a broken one. If a colleague reports that the chain icon is missing from their cards, that parameter is the place to look.

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Only the Configured Roles Count

Reading the board follows the same rule as writing it. Scheduler inspects each task’s outgoing work item links and treats a link as a dependency only if its role is one of the roles listed in Dependency Roles. A work item may therefore carry plenty of links — relates to, verifies, parent — and still show no dependency arrow, because none of those roles is configured as a dependency role for this board. Two boards over the same project can legitimately disagree about what counts as a dependency, simply because they list different roles.

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Direction: Predecessor and Dependent

Dependencies are directional, and the direction comes from the order in which you click the two Add Link handles. The card whose handle you click first is the predecessor — the task that comes first. The second is the dependent — the task that follows it. Scheduler writes the link onto the dependent work item, pointing back at the predecessor, which is the natural reading of a “depends on”-style role: the follower declares what it waits for. On the board, the arrow runs from the predecessor to the dependent, with the arrowhead on the dependent — so an arrow always points at the task that is waiting. Clicking the same pair of handles again removes the link, and removal writes through to Polarion the same way creation does. Link Task Dependencies walks through the gesture in detail.

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The Overlay Draws Only What It Can See

Dependency arrows are not drawn permanently. They are an overlay you turn on with the Show Dependencies toolbar button, and Scheduler draws each arrow between the two task bars as they currently sit on screen. That has a consequence worth internalising: an arrow can only be drawn between two tasks that both have a bar on the board. For an arrow to appear, both ends must be

• scheduled — an item sitting in the Unplanned sidebar has no bar to attach an arrow to, and
• inside the visible timeline window — a partner whose dates fall outside the range the board is currently showing has no bar either.

When one end is missing, the link is still recorded in Polarion and still perfectly valid; only its arrow is absent. So a task that appears to have no dependencies may simply have partners the board is not currently showing. Two more behaviours of the overlay:

• Turning it on expands collapsed rows first, so that arrows are not drawn to bars hidden inside a folded swimlane.
• While it is on, a Click here to hide dependencies helper appears; using it — or clicking anywhere on the overlay — clears the arrows. The overlay is transient, so an action that redraws the timeline, such as Scroll to today, also clears it.

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Unplanning and Dependencies

Unplanning a task clears its schedule and returns it to the Unplanned sidebar. Its bar disappears from the timeline, and with the bar go any arrows attached to it. The work item and its links are untouched. Schedule the task again and, with Show Dependencies on, its arrows come back.

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See Also

• Link Task Dependencies — configure a Dependency Role and create, inspect and remove links on the board
• Board and Timeline — the timeline window that decides which tasks are visible at all
• Dates, Duration and Effort — what makes a task scheduled in the first place
• Toolbar Controls — Show Dependencies and the rest of the toolbar
• Widget Parameters — the Dependency Roles parameter and its neighbours