Definition
Monte Carlo Forecasting
Monte Carlo forecasting predicts delivery by running thousands of simulated futures from a team's historical throughput, producing a probability rather than a single date. Instead of 'we'll finish on the 20th,' it answers 'an 85% chance of finishing by the 24th.' It replaces false-precision estimates with honest, evidence-based ranges drawn from how the team actually performs.
Key takeaways
- Monte Carlo forecasting runs thousands of simulated futures from a team's historical throughput to produce a probability, not a single date.
- It answers 'an 85% chance of finishing by the 24th' instead of a point estimate that's almost certainly wrong.
- It needs no story points — only the completion data a team already has — and naturally accounts for good and bad weeks.
- Its main assumption is that the future resembles the recent past, so it works best when the team and work type are stable.
The method is simpler than its name suggests. Take a team's recent throughput — how many items it completed each week — as a sample of how it really behaves. To forecast finishing some number of items, randomly draw from that history week after week, accumulating completions until the work is done, and record how long it took. Do that thousands of times and you get not one answer but a distribution of outcomes, because each simulated future draws a different sequence of good and bad weeks.
That distribution is the forecast. Rather than a single date that is almost certainly wrong, you read percentiles: there might be a 50% chance of finishing by one date and an 85% chance by a later one. This lets a team commit at a confidence level it chooses — conservative for an external promise, aggressive for an internal stretch — and communicate uncertainty honestly instead of hiding it behind a point estimate.
Its great advantage is that it needs no story points or estimation at all — only the completion data a team already generates. It also naturally accounts for variability, including the bad weeks that single-number plans always forget. The main caveat is that it assumes the future resembles the recent past, so it works best when the team and the type of work are reasonably stable.
Planoda charts throughput per period from completion events, the raw material a Monte Carlo forecast runs on — so delivery questions can be answered with a probability grounded in real history rather than an optimistic guess.
Related terms
- ThroughputThroughput is the number of work items a team completes in a given period — issues finished per week, for example. It is the simplest flow metric: a direct count of output over time. Tracked across periods, throughput reveals a team's real delivery capacity and is the basis for probabilistic, estimate-free forecasting.
- VelocityVelocity is the average amount of work a team completes per cycle, measured in issues or story points. By tracking it over several cycles, teams forecast how much they can realistically take on next. Velocity is a planning aid for a specific team over time — never a target to maximize or a way to compare teams against each other.
- Cycle TimeCycle time is how long an issue takes from the moment work actively starts on it to the moment it is done. Measured in hours or days, it captures the team's hands-on flow efficiency. Shorter, more consistent cycle times mean a more predictable system — the core flow metric Kanban teams optimize.
- Burnup ChartA burnup chart tracks completed work rising toward a total-scope line over time. Unlike a burndown, which only shows remaining work falling toward zero, a burnup plots two lines — work done and total scope — so scope changes are visible as movement in the upper line. It distinguishes 'falling behind' from 'scope was added.'