Fusion scheduling basics

Fusion Online and Fusion Desktop are designed around the principles of critical chain and the ProChain System, helping you plan, schedule, and deliver projects more effectively. This page provides a high-level overview of how Fusion’s scheduling engine works, why it’s different, and how to interpret what you see after scheduling a project.

If you're new to project scheduling in Fusion, this page is a great starting point. For a deeper dive into scheduling theory, see the Concepts section.

Projects as models

In Fusion, a project network is a model of how work is planned to proceed. It captures your team’s approach using:

Tasks – the work to be done
Dependencies – the order in which tasks must occur
Durations – how long tasks are expected to take

This model can also reflect:

Resource limitations, if you assign roles to tasks
Working time constraints, such as weekends or holidays from the project calendar

Once the network is built and scheduled, Fusion generates both tabular data and graphical insights—such as Fever Charts and Impact Chains—to help you understand your project’s status and risks.

Critical chain and buffers

Unlike traditional scheduling methods that focus on early start/early finish dates, Fusion uses Critical Chain logic to identify the longest chain of dependent tasks that drives the project’s completion.

Instead of adding safety time to every task, Critical Chain introduces a project buffer at the end of the schedule to protect the endpoint. This approach makes safety time visible and manageable, helping task owners focus on what’s important and minimize the safety time that's actually needed.

What Is an endpoint?

An endpoint represents a major project deliverable or milestone. Ideally, your network has a single endpoint—but you can define as many as you need to communicate important milestone status externally.

Durations: planning with ranges

Task durations in Fusion can be defined as a range, rather than a fixed number.

The focus duration represents how long the task should take if the assignee gives it focused attention
The low-risk duration reflects a realistic upper bound if minor issues arise

This lets you plan realistically, without artificially precise estimates. Buffers at the end of the chain absorb that variability instead of trying to eliminate it from every task.

Scheduling and updating

When you reschedule a new project, Fusion uses your project model to:

Calculate the critical chain
Add buffers to endpoints
Generate a realistic project schedule
Calculate various progress indicators

When you update a project in execution, Fusion recalculates all these values. However, it retains a baseline schedule, including existing buffers and their history, so that you can track progress over time.

Tracking progress and analyzing risk

Fusion gives you tools to interpret and react to schedule updates:

Fever Charts – Visualize progress vs. buffer consumption to see if your project is on track
Impact Chains – Analyze the chain of tasks contributing to buffer consumption and reduce risk by improving flow
Resource Views – After scheduling with resource assignments, you can analyze resource load to identify overallocations or areas where team members may be underutilized. Use My Resources or the Resources tab in Project Details to monitor workloads and capacity.

These insights help you make better decisions about where to focus effort and how to reduce schedule risk.