Analyze the impact chain

The impact chain is one of the most powerful tools in Fusion for understanding what’s driving buffer consumption and where your project may be at risk. After updating the project schedule, the impact chain provides a clear, prioritized view of the tasks that are currently putting pressure on your project buffer—or are close to doing so.

This allows project managers to shift focus from low-impact tasks to priority tasks, helping prevent delays and ensure critical work gets the attention it needs.

What is the impact chain?

The impact chain shows a sequence of tasks that, if delayed, will directly impact the project buffer. These tasks represent the critical chain leading to the selected endpoint under the current schedule update. Fusion also supports analysis of shadow chains—tasks that are close to becoming critical and could impact the buffer if conditions change.

You can access the impact chain for any endpoint from:

The Endpoints tab in Project Details
My Endpoints view
From the endpoint’s action menu, click View Impact Chain

Using the Impact Chain view

When you open the impact chain, you’ll see a task list ranked in projected start order. Fusion also provides several controls to help you focus your analysis:

Horizon filter

Use this to filter the list down to tasks projected to start within a certain number of days. This helps focus on near-term work that’s actionable now.

Sensitivity filter

Adjusting the sensitivity lets you expand the chain to include shadow chains—tasks that are not currently on the impact chain but are near enough to affect the buffer if their duration increases or progress slows.

This helps project managers look ahead and spot risks before they become urgent.

Tips for analyzing the chain

To identify which tasks may need action or follow-up:

Look for eligible tasks – These are tasks that are ready to start (no incomplete predecessors or blocking constraints). They represent the most immediate opportunities to make progress and reduce risk.
Check successors – For tasks that are nearly done or in progress, look at their successors to see where the baton needs to be handed off. Ensuring a smooth handoff helps maintain momentum on the chain.
Examine not-yet-eligible tasks – For tasks that are projected to start soon but are not yet eligible, check what’s blocking them. Open the Task Links view (available from the action menu in the Task Name column) to see their predecessors and determine if delays upstream are holding them back.
Add the Update Date column – This helps you spot tasks that may be out of date and need follow-up.
Add the Assignee column – Make sure every task has clear ownership so that next steps are not delayed.
Review Projected Start and Remaining Duration – These fields help you understand how much work remains and when it's expected to begin.
Question dependency assumptions – While reviewing tasks in the impact chain, it's important to question whether the dependencies reflect reality. Sometimes tasks are:
- Missing key links, which can lead to unrealistic scheduling and underestimated risk
- Linked unnecessarily, creating artificial delays or making the chain longer than it needs to be
Consider whether each dependency is truly required, or if the schedule could be improved by removing or adjusting certain links. This kind of critical thinking helps ensure the impact chain is not just a reflection of the model—but an accurate model of the work.

Using these techniques, project managers can stay proactive—removing blockers, confirming ownership, and focusing the team on the tasks that matter most to protecting the buffer.

Why it matters

The impact chain isn’t just another list of tasks—it’s a risk-prioritized task list that highlights what matters most right now.

It helps you make informed trade-offs about where to apply limited resources
It surfaces early warnings for tasks nearing the critical path
It supports collaborative planning by showing teams exactly what needs to happen next to keep the project on track