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Schedule Risk

The Schedule Risk view runs a Monte Carlo simulation over your schedule and reports the project finish as a probability distribution rather than a single date. Each task's duration is sampled from its PERT three-point estimate, the simulation runs the network many times, and the results are aggregated into a completion-probability curve and a per-task criticality index.

Sidebar location: Track → Schedule Risk (/projects/schedule-risk).

What an estimate needs

Each task can carry a three-point PERT estimate:

  • Optimistic — fastest plausible duration.
  • Most likely — your best single-point estimate.
  • Pessimistic — slowest plausible duration.

The wider and more honest the spread, the more meaningful the output. Tasks without three-point estimates contribute their fixed duration.

What you see

  • Duration percentiles — P10 (best), P50 (median), P80, and P95 (worst) completion estimates.
  • Completion probability — for a target date, the chance of finishing on or before it. The deterministic Gantt finish typically lands near P50.
  • Criticality index — for each task, how often it landed on the critical path across all iterations. High-criticality tasks are the real schedule drivers, even if they are not on today's deterministic critical path.

Walkthrough

  1. Open Track → Schedule Risk.
  2. Set Iterations — more iterations give tighter, more stable percentiles.
  3. Click to run the simulation. The page reports the duration percentiles, completion probability, and the top schedule drivers ranked by criticality index.
  4. Read the percentiles: if you need higher confidence than the median, plan against P80 or P95 rather than P50.
  5. Read the criticality index. Tasks at the top dominate schedule risk — manage them first. A task with high estimate variance can dominate risk even when its mean duration suggests it has slack.

AI Assistant prompts

Run a Monte Carlo schedule simulation and explain the top three tasks by criticality index.

Where does the Monte Carlo criticality index diverge from the deterministic critical path, and why?

Recommend three actions to pull P80 in by one week.

Tips

  • Make PERT spreads honest. A one-day spread is rarely realistic; calibration usually means wider than your gut says.
  • Re-run after every plan change. Estimates are forward-looking — once a task is done its variance is gone.
  • Quote a confidence level. Stakeholders hear "the schedule" as a commitment; pair the date with a probability.

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