Critical Path

The critical path is the longest sequence of dependent tasks that determines the minimum project duration. Understanding and monitoring the critical path helps you identify which tasks directly impact your project's end date.

What is Critical Path?

Definition

The critical path is:

• The longest path through dependent tasks
• The sequence with zero float (slack)
• Tasks that directly determine project end date

Importance

Critical path tasks:

• Cannot be delayed without delaying the project
• Require closest monitoring
• Should receive priority resources

Viewing Critical Path

Enabling Display

1. Open your plan's Timeline view
2. Find view options or settings
3. Toggle Show Critical Path
4. Critical tasks highlight

Visual Indicators

Critical path tasks appear with:

• Different color (typically red)
• Bold or highlighted bars
• Connected dependency lines emphasized

Understanding Float

What is Float?

Float (or slack) is the amount of time a task can be delayed without affecting:

• Total Float - Project end date
• Free Float - Successor task start date

Float Values

Viewing Float

Float information may appear:

• In task details panel
• As column in task list
• In tooltip on hover

Critical Path Calculation

How It's Calculated

YAPL calculates critical path using:

1. Forward Pass - Calculate earliest start/finish for each task
2. Backward Pass - Calculate latest start/finish from end date
3. Float Calculation - Difference between latest and earliest dates
4. Path Identification - Tasks with zero float are critical

Automatic Updates

Critical path recalculates when:

• Task dates change
• Dependencies are modified
• Progress is updated
• New tasks are added

Multiple Critical Paths

When They Occur

Multiple critical paths exist when:

• Parallel task sequences have equal duration
• Multiple paths tie for longest

Display

All critical paths are highlighted:

• May use same visual treatment
• All affect project end date equally

Near-Critical Tasks

What They Are

Near-critical tasks have:

• Very small float (e.g., less than 5 days)
• Risk of becoming critical
• Should be monitored closely

Monitoring

Watch near-critical tasks because:

• Small delays push them critical
• May have multiple paths at risk
• Provides early warning

Using Critical Path

Project Planning

Use critical path to:

• Validate schedule logic
• Identify key milestones
• Plan resource allocation
• Set priorities

Progress Monitoring

During execution:

• Track critical task progress closely
• Address delays immediately
• Watch for path changes

Recovery Planning

When behind schedule:

• Focus on critical path tasks
• Look for crash opportunities
• Consider fast-tracking options

Critical Path Changes

Why It Changes

Critical path can shift due to:

• Task delays (critical or non-critical)
• Faster-than-expected progress
• Scope changes
• Resource reallocation

Monitoring Changes

Watch for:

• New tasks becoming critical
• Previous critical tasks gaining float
• Multiple paths becoming critical

Schedule Compression

Crashing

Reduce duration by adding resources:

• Focus on critical path tasks
• Consider cost/benefit
• May not always be possible

Fast-Tracking

Perform tasks in parallel:

• Overlap sequential tasks
• Increases risk
• Reduces total duration

Trade-offs

Best Practices

Regular Review

• Check critical path weekly
• Note any path changes
• Update stakeholders

Focus Resources

• Assign best resources to critical tasks
• Minimize interruptions
• Prioritize support

Contingency Planning

• Identify backup plans for critical tasks
• Build buffer into non-critical tasks
• Have recovery strategies ready

Documentation

• Record critical path at project start
• Document changes over time
• Use for lessons learned

Critical Path in Reports

Including in Exports

When exporting Gantt:

• Critical path highlighting included
• Legend explains colors
• Dates and float visible

Stakeholder Communication

Use critical path to show:

• What determines the end date
• Where delays will hurt
• Priority areas

Troubleshooting

No Critical Path Displayed

• Verify tasks have dependencies
• Check that dates are set
• Enable critical path view option
• Ensure Professional tier subscription

Unexpected Critical Path

• Review all dependencies
• Check for missing links
• Verify task durations
• Look for constraints affecting dates

Critical Path Keeps Changing

• Normal during project changes
• Review what's causing shifts
• May indicate planning issues
• Could mean too much parallelism

All Tasks Show as Critical

• Missing dependencies between tasks
• Tasks not properly linked
• May need better WBS structure

Related Topics

• Timeline View - Viewing the chart
• Editing Timeline - Making changes
• Baseline Comparison - Tracking variance