Schedule Variance Analysis

Overview

Schedule variance (SV) measures how closely a project's actual progress aligns with its planned timeline. It represents the difference between the value of work completed and the value of work scheduled to be completed by a specific date.

Formula

SV = EV - PV

or

SV = BCWP - BCWS

Where:

• EV (Earned Value): Sum of all budgeted costs of completed work
• PV (Planned Value): Budgeted cost of planned tasks
• BCWP: Budgeted Cost of Work Performed
• BCWS: Budgeted Cost of Work Scheduled

Interpreting Results

Positive Schedule Variance (SV > 0)

• Project is ahead of schedule
• Completed more work than planned
• Good indicator of project health

Zero Schedule Variance (SV = 0)

• Project is exactly on schedule
• Work completed matches plan
• Ideal situation

Negative Schedule Variance (SV < 0)

• Project is behind schedule
• Less work completed than planned
• Requires corrective action

Duration Variance

Related metric from Microsoft Project:

Duration Variance = Duration - Baseline Duration

• Negative number: Task taking less time than originally planned
• Positive number: Task taking more time than planned
• Zero: Task taking exactly as much time as planned

Benefits

• Identifies deviations from planned schedule
• Enables early corrective actions
• Provides objective performance measure
• Supports data-driven decision making
• Facilitates stakeholder communication
• Helps predict project completion date

Best Practices

1. Calculate variance regularly (weekly or bi-weekly)
2. Analyze trends over time, not just single points
3. Investigate root causes of variances
4. Take corrective action promptly
5. Update project plans based on learnings
6. Communicate variances to stakeholders

Integration with Time Tracking

• Time tracking provides actual hours worked (basis for EV)
• Planned time provides PV baseline
• Comparison reveals schedule performance
• Supports accurate forecasting
• Identifies underperforming tasks or resources

Related Metrics

• Cost Variance (CV): EV - AC
• Schedule Performance Index (SPI): EV / PV
• Cost Performance Index (CPI): EV / AC
• Estimate at Completion (EAC): Forecasted final cost
• Estimate to Complete (ETC): Cost to finish remaining work