Project Inputs
Use the responsive three column, two column, and one column form layout to model critical activities, schedule lag, and recovery assumptions.
Example Data Table
This sample demonstrates how sequential critical activities can create a measurable project delay.
| Activity | Planned Days | Actual Days | Lag Days | Effective Actual | Variance |
|---|---|---|---|---|---|
| Detailed Design | 12 | 14 | 1 | 15 | 3 |
| Procurement | 18 | 20 | 2 | 22 | 4 |
| Fabrication | 22 | 24 | 1 | 25 | 3 |
| Site Installation | 16 | 17 | 0 | 17 | 1 |
Sample totals: baseline path 68 days, current path 79 days, gross delay 11 days, and net delay depends on approved extensions and recovery measures.
Formula Used
Baseline Critical Path Duration = Sum of planned activity durations
Current Critical Path Duration = Sum of actual activity durations + lag impacts
Gross Delay = max(0, Current Duration − Baseline Duration)
Adjusted Gross Delay = Gross Delay × Concurrency Factor
Adjusted Contract Duration = Baseline Duration + Approved Extension
Forecast Mitigated Duration = max(0, Current Duration − Recovery Days)
Net Delay = max(0, Forecast Mitigated Duration − Adjusted Contract Duration)
Delay Cost Exposure = Net Delay × Daily Indirect Cost
Float remaining equals total available float minus adjusted gross delay. Completion efficiency equals actual percent complete divided by planned percent complete, multiplied by 100.
How to Use This Calculator
- Enter project controls such as float, approved extensions, recovery days, daily indirect cost, and progress percentages.
- Add each critical path activity as a separate card with planned duration, actual duration, and any extra lag impact.
- Use the concurrency factor to discount overlapping delay when multiple events happen at the same time.
- Click Calculate Delay to show results above the form and review summary metrics, dates, and activity-level contributions.
- Export the calculated result to CSV or PDF for reports, claims review, internal meetings, or schedule recovery planning.
FAQs
1. What does this calculator measure?
It measures delay on the critical path by comparing planned durations against actual durations and lag impacts. It also estimates float erosion, contractual delay, and cost exposure.
2. Why should I enter only critical activities?
Only critical path activities directly influence overall completion. Noncritical activities may slip without delaying the project if their float absorbs the variance.
3. What is lag impact in this tool?
Lag impact captures waiting time added between critical activities, such as approvals, cure periods, logistics gaps, or hold points that extend the effective path duration.
4. How does the concurrency factor work?
It reduces gross delay when overlapping events happen together. A value of 1 keeps full impact. Smaller values discount concurrent delay to reflect shared schedule effect.
5. What is the difference between gross and net delay?
Gross delay compares current critical duration against baseline. Net delay then considers approved extensions and recovery efforts to show remaining contractual exposure.
6. How is float remaining calculated?
The calculator subtracts adjusted gross delay from available float. Positive float means some buffer remains. Negative float indicates the schedule has already overrun available flexibility.
7. Can I use this for recovery planning?
Yes. Enter recovery or acceleration days to see how mitigation changes forecast duration, contractual delay, and expected cost exposure before committing resources.
8. Does this replace a full CPM scheduling analysis?
No. It is a fast decision-support tool. Detailed claims, forensic delay analysis, or multi-calendar CPM models still need a full scheduling review.