An Alternative to Estimations: Planning Your Sprints and Projects with Monte Carlo Simulation

"Planning isn’t about predicting the future. It’s about preparing for it."

Most teams still try to plan with a single number:

“We’ll be done in 3 sprints.”

But real work doesn’t behave like that. Some work flies, some gets stuck, and surprises are guaranteed.

Complexity and Randomness

That’s what I call the “randomness of the system” - very suggestively shown on the chart below.
The navy blue rectangle shows time (average time, it’s from JIRA) in an “on hold” status in the last four sprints. This team noticed that they spend more time waiting on others than actively working on an item. And look how long the wait can be! That’s precisely the randomness of the system.

Here’s where Flow Metrics and Monte Carlo Simulations come in — not as crystal balls, but as weather forecasts for your delivery.

Step 1: Measure What Matters

Start with Flow Metrics like:

• Cycle Time – how long things usually take

• Throughput – how many things you finish per week/sprint

These aren’t just numbers—they’re your team’s rhythm. They tell the story of how work actually flows through your system.

"You don’t need more estimates. You need better evidence."

Work Items Completed in last 30 days - Let People Work Lighthouse tool

Step 2: Simulate, Don’t Speculate

Monte Carlo Simulations take your real data and run thousands of ‘what if’ scenarios—faster than you can blink.

Instead of saying:

• “We’ll definitely finish 15 stories.”

You say:

• “Based on our past 6 months, we have an 85% chance of finishing 12 to 16 stories in the next 3 sprints.”

That’s a probabilistic forecast—and it’s both honest and actionable.

"Hope is not a strategy. Probability is."

Probability distribution

Why We Love It?

• Less arguing over estimates

• More confidence in planning

• Smarter trade-offs when stakeholders ask for more, sooner

You move from guessing a date to managing a range and probability.

"It’s like moving from a coin toss to a weather app: it won’t be perfect, but you’ll know if you need an umbrella."

One-click simulation with the Lighthouse tool

Watch or listen to our conversation, where we explain why estimates are a waste of time and how to leverage the data you already have: throughput to start creating Monte Carlo Simulations and get better informed about your forecasts.

We go step by step and explain it clearly.

Benjamin Huser-Berta

shares the tool he built to facilitate that for free. Now you can get your simulations with one click of a button!

I know, sounds too good to be true! Check it out for yourselves!