Analyze delays

When a project begins to fall behind, it’s important to understand why—not just what is delayed. Fusion Online provides tools to help you analyze schedule changes between updates so you can identify the causes of delay, communicate them clearly, and take informed action to stay on track.

When to analyze delays

After you update the project schedule, you might notice:

An increase in buffer consumption
A shift in the estimated landing zone in the Fever Chart
New or unexpected tasks appearing in the impact chain

These are signals that something in the network has changed—and you need to find out what.

How to analyze delays in Fusion Online

Fusion Online makes it easy to compare the current schedule against previous updates to spot what’s changed:

Use the Task History view

To see how a task’s timing or status has changed over time:

Click on the task name in any task view to open the Task Details view.
Click the Task History tab.

This view shows:

Changes to duration, start, and finish projections
Updates to task status or completion
When each change was made and who made it

This is a useful way to trace the source of delays on specific tasks and identify patterns—such as slow updates, repeated re-estimating, or tasks that are blocking others.

Use the Network Differences report

To see how the overall project network has changed over time, you can use the Network Differences report to compare two snapshots of the project:

Open the Project Details view.
Click the Project History tab.
From the list of update records, open the action menu (...) for any history entry.
Select View Differences and choose another history record to compare it with.

The report will highlight all meaningful changes in the project network between the two snapshots, including:

Added or removed tasks
Changes in durations, links, or resource assignments

This is a powerful tool for identifying what changed between schedule updates—whether progress slowed, new work was added, or logic shifted in a way that affected the timeline.

Use the Impact Chain

If your schedule update shows increased buffer consumption, the Impact Chain can help you understand what’s driving the change.

The impact chain highlights the sequence of tasks that are contributing to buffer usage and lets you analyze upstream causes of delay. You can review tasks projected to start soon, investigate dependencies, and assess whether updates are current and assignments are clear.

For detailed guidance, see Analyze the impact chain.

Common causes of delay

Some frequent culprits include:

Incomplete predecessor tasks – Tasks that should have started but are blocked by work that hasn’t been finished.
Outdated task updates – If a task hasn’t been updated, it can lead to an inaccurate picture of progress. The task might appear delayed when progress has actually been made but not recorded, or it might be even further behind than expected because no progress has occurred and the delay hasn’t been acknowledged.
Unrealistic duration estimates – Durations that were too optimistic (or too padded) can distort the schedule.
Unassigned or misassigned tasks – Tasks with no assignee or assigned to the wrong person can sit idle.
Resource bottlenecks – If scheduling with resource constraints, limited availability can push tasks later.
Incorrect dependency assumptions – Sometimes tasks are missing critical links or have unnecessary dependencies. A missing link can prevent the system from properly modeling risk, while an unnecessary link can create artificial delays. Reviewing task relationships can reveal opportunities to correct or simplify the logic.