Task Dependencies and Cascade

Dependencies are the backbone of any construction schedule. They define the order in which work must happen and ensure that delays on one task automatically ripple through to everything that depends on it. BuildChart supports two dependency types and handles cascade logic automatically.

Dependency Types

Finish-to-Start is the most common type. It means Task B cannot start until Task A finishes. For example, you cannot start drywall until framing is complete. When you link framing to drywall with a finish-to-start dependency, BuildChart enforces that relationship throughout the schedule.

Concurrent means two tasks run in parallel. They have a logical relationship — you want to track that they are related — but neither blocks the other. Electrical rough-in and plumbing rough-in often run concurrently. Concurrent dependencies do not trigger cascade shifts.

How to Add a Dependency

1. Open the task form by clicking a task or pressing Enter on a selected task.
2. Scroll down to the Dependencies section.
3. Select the predecessor task from the dropdown.
4. Choose the dependency type — Finish-to-Start or Concurrent.
5. Save the task. The dependency arrow appears on the Gantt chart immediately.

To remove a dependency, open the same task form and click the X icon next to the dependency you want to delete.

Cascade Logic

When a task’s end date changes, BuildChart calculates the variance — the difference in days between the old end date and the new end date. It then walks through every finish-to-start dependent task recursively and shifts their start and end dates by that same variance.

For example, if framing was scheduled to end on March 14 but now ends on March 21 (a 7-day slip), every task that depends on framing — and every task that depends on those tasks — shifts forward by 7 days. This cascading update happens in a single operation so the entire schedule stays consistent.

Dependency Arrows

The Gantt chart draws SVG arrows between linked tasks. Each arrow starts at the end of the predecessor bar and curves to the start of the dependent bar. These arrows update in real time as you drag bars or edit dates, so you always have a visual map of your critical path.

Deadline Warnings

Every project has a hard deadline (the project end date). If a cascade pushes any task’s end date past that deadline, BuildChart displays a yellow warning banner. This early warning gives you time to adjust the schedule, add resources, or negotiate a new completion date before the overrun becomes a problem on site.