Get P50, P80 and P90 finish dates from a schedule file

The Schedule Risk Analyzer is a free tool that answers one question about a schedule file: how likely is the finish date? It runs a Monte Carlo simulation of the plan and returns three dates you can commit to, with no Onplana account.

Run an analysis

1. Open onplana.com/tools/schedule-risk and upload a Microsoft Project .mpp, a Project XML (MSPDI) file or a Primavera P6 .xer, up to 22 MB.

2. Read the result. It shows three dates and the five tasks that move the finish most:

   • P50: half the runs finished on or before this date.
   • P80: 80% of the runs finished on or before it, a common commitment date.
   • P90: 90% of the runs finished on or before it.

   It also shows the finish date in your file and the share of runs that met it.

3. To see the full report, enter your email. The full report shows how the finish dates spread, every task that drives the finish, and each task’s P80 finish date beside its planned one.

How the simulation works

Each run varies every task that still has work left, then schedules the plan through its links, lags and constraints, as Onplana’s critical path engine does, and records the finish.

• A task’s duration is drawn from a triangular range of 10% under to 25% over its planned duration, so overruns are more likely than early finishes.
• Done tasks and milestones keep their dates. A started task varies only the work it has left when the file has a status date.
• Summary tasks are not varied: their dates come from the tasks under them.
• The tool aims for 2,000 runs, and runs fewer on a very large schedule so the answer arrives in seconds. The report says how many it ran.
• The same file always gives the same dates.

What the free tool does not do

Caution

Durations are drawn independently and with one default range, so the spread is narrower than on a real project, where late tasks tend to be late together. Treat the P80 as a floor rather than a ceiling.

• It schedules a Monday to Friday week at the hours per day in your file, without your holidays or exceptions.
• It reads task dates as whole days and does not level resources.
• It runs schedules of up to 2,000 tasks with work.

Keep the schedule in Onplana

From the full report, Save to Onplana creates a free workspace with the same file imported as a project. On a plan that includes it, the in-app schedule risk analysis reruns the simulation on the live project, with your own optimistic and pessimistic duration for each task and the risks on your register.

FAQ

Is my file kept? The parsed plan is kept with your result so the report and the Save to Onplana step work. The raw file is not kept, and no AI model reads it.

Why is the chance of my own finish date so low? The date in a plan assumes every task takes exactly its planned duration. With a range that leans late, few runs do, so a chance under 50% is normal.