Baseline & Comparison
Applies to: Free · Pro · Enterprise Last updated: 08-Jun-2026
Overview
When a baseline schedule is loaded alongside the current schedule, the AI Copilot becomes baseline-aware. It automatically shows current vs baseline values, calculates variance, and highlights activities that slipped, improved, were added, or were deleted. This page covers how baseline awareness works, the comparison tools available through the Copilot, and how to generate variance reports.
Baseline Awareness
Automatic Context Injection
When a baseline is loaded, the Copilot's system prompt includes:
- Baseline project name and data date
- Baseline activity count and completion percentage
- BL_ prefix fields for every activity (BL start, BL finish, BL duration, BL total float)
This context is injected automatically — you don't need to ask for it.
What Changes in Copilot Behaviour
| Without Baseline | With Baseline |
|---|---|
| Shows current values only | Shows current and baseline values side by side |
| No variance data | Calculates start variance, finish variance, duration variance, and float variance |
| Standard activity details | Flags activities as slipped, improved, added, or deleted |
| Progress columns only | Offers to add BL and Variance columns to the grid |
Asking About Variance
When a baseline is loaded, you can ask variance questions directly:
Example prompts:
- "What slipped from the baseline?"
- "Show me activities where the finish date moved by more than 10 days"
- "Which activities have a negative start variance?"
- "Compare the current critical path with the baseline"
Percentage Types
The Copilot understands all P6 percentage types and shows them when relevant:
| Type | Field | Description |
|---|---|---|
| Physical % | phys_complete_pct | Manually entered physical progress |
| Duration % | Duration-based | Calculated from elapsed vs remaining duration |
| Labour Units % | Labour hours | Actual labour hours / budget labour hours |
| Non-Labour Units % | Non-labour hours | Actual non-labour / budget non-labour |
| Cost % | Costs | Actual cost / budget cost |
| Schedule % | Schedule-based | Based on dates relative to data date |
When you ask about completion percentage, the Copilot shows all applicable percentage types by default so you can compare them.
Comparison Tools
The Copilot has five tools for baseline comparison analysis. These are categorised as read/integration tools — they don't modify data.
run_comparison
Trigger a baseline comparison analysis (or check if one has already been run).
No parameters required.
get_comparison_results
Get the latest comparison summary: baseline vs current statistics, top-impact changes, and counts of added, deleted, and changed activities.
No parameters required.
Example prompts:
- "What changed since the last baseline?"
- "Give me the comparison summary"
- "How many activities were added or removed?"
get_comparison_changes
Get detailed field-by-field comparison changes, filtered by type and impact level.
| Parameter | Required | Description |
|---|---|---|
changeType | No | added, deleted, or changed |
impactLevel | No | critical, high, medium, low, or none |
criticalPathOnly | No | Show only critical-path changes |
limit | No | Max items (default 50) |
Example prompts:
- "Show all critical-impact changes"
- "Which activities were deleted since the baseline?"
- "What changed on the critical path?"
- "Show me high-impact date changes"
filter_comparison_in_grid
Filter the Activities grid to show comparison changes. Automatically switches to the Activities tab.
| Parameter | Required | Description |
|---|---|---|
changeType | No | added, deleted, or changed |
impactLevel | No | critical, high, medium, or low |
Example prompts:
- "Filter the grid to show added activities"
- "Show deleted activities in the grid"
- "Filter to critical-impact changes"
generate_comparison_narrative
Generate a professional narrative report from the comparison results. Covers key changes, impact analysis, date movements, and recommendations.
No parameters required.
See Narratives & Export for export options.
Comparison Workflow
Step 1 — Load the Baseline
Load a baseline schedule by marking a schedule version as the baseline in the Projects tab. See Current/Baseline Marking for details.
Step 2 — Run the Comparison
Navigate to the Comparison tab and run the comparison, or ask the Copilot:
- "Run the baseline comparison"
- "Compare current vs baseline"
Step 3 — Analyse Results
Ask the Copilot to summarise or drill into specific areas:
- "What's the comparison summary?"
- "Show me all critical-impact changes"
- "Which activities slipped by more than a week?"
Step 4 — Filter and Inspect
Ask the Copilot to filter the grid so you can inspect changes visually:
- "Filter the grid to changed activities"
- "Show only high-impact changes in the grid"
- "Apply the updated programme column preset"
Step 5 — Generate a Report
Export a professional variance report:
- "Generate a comparison narrative"
- "Export the comparison report as DOCX"
- "Create a change log of all major changes"
Variance Column Suggestions
When baseline data is available and you ask about progress or changes, the Copilot may suggest adding variance columns to the grid:
| Column | Description |
|---|---|
| BL Start | Baseline early start date |
| BL Finish | Baseline early finish date |
| BL Duration | Baseline original duration |
| BL Total Float | Baseline total float |
| Start Variance | Current start − baseline start (days) |
| Finish Variance | Current finish − baseline finish (days) |
You can add these manually with "add BL start and start variance to the grid" or apply the Updated Programme preset which includes them.
Impact Levels
Comparison changes are categorised by impact level:
| Level | Criteria |
|---|---|
| Critical | Activity on critical path with significant date movement |
| High | Date change > 10 days or status change (added/deleted) |
| Medium | Date change 5–10 days or duration change |
| Low | Date change < 5 days or minor field changes |
| None | No meaningful variance detected |
Tips & Best Practices
- Load the baseline first — the Copilot can't show variance data without a baseline schedule.
- Run comparison before asking — comparison results must be generated before the Copilot can query them.
- Use impact filters — "Show critical and high impact changes" focuses on what matters most.
- Combine with quality — "What's the quality score of the changed activities?" cross-references comparison and quality data.
- Export for submissions — generate a comparison narrative and export as DOCX for client or PMO submissions.
- Track critical path changes — use
criticalPathOnlyto focus on changes that affect the project finish date.
Troubleshooting
| Problem | Cause | Solution |
|---|---|---|
| "No comparison results available" | Comparison not run yet | Run comparison from the Comparison tab or ask the Copilot |
| "No baseline loaded" | No schedule marked as baseline | Mark a schedule version as baseline in the Projects tab |
| Variance values are zero | Baseline and current are the same version | Select a different baseline version |
| Missing BL columns | Columns not added to grid | Ask the Copilot to "add BL start and BL finish" or apply the Baseline preset |