Sprint Forecasts
That land.
Most sprint forecasts miss because they're built on the mean. Forecast at p85 instead and build the tail into the budget.
The forecasting problem
Cycle times have long tails. A few stories take 5-10× the median because of blocked dependencies, hidden complexity, scope ambiguity. Those don't move the median much, but they wreck individual dates.
Forecast at the mean and 86% of sprints miss. Forecast at p85 and dates start landing.
The toolkit (in order)
1. Read: Forecasting at p85
10-min guide. Why the mean lies, the math, the stakeholder message, four anti-patterns to avoid.
- The math behind p85
- The stakeholder script
- Anti-patterns to refuse
2. Analyse: Cycle Time Calculator
Paste raw cycle times. Get count, mean, p50/p85/p95, min/max, histogram, and a tail-shape diagnosis.
- Linear-interpolation percentiles
- Histogram + tail diagnosis
- Markdown export
3. Forecast: Monte Carlo at p85
Simulate the sprint 10,000 times. Get the p85 completion date. Defensible numbers for stakeholders.
- 10,000-run Monte Carlo
- p50, p85, p95 ranges
- Confidence-interval output
4. Track: Burndown Chart Generator
Once committed, track in-flight. SVG burndown with ideal line, completion %, and pattern diagnosis.
- Hockey-stick detection
- Late-slip diagnosis
- Download as SVG
Related reading
Agile metrics that actually help
Velocity, throughput, cycle time, WIP; what each tells you, what it doesn't, and which to skip. The Goodhart trap and how to avoid it.
ReadVelocity dropped: the actual playbook
When a dip is noise vs signal. Seven real causes in order of probability. The one-meeting planning fix. What NOT to do under pressure.
ReadBurndown charts: when they help, when they lie
What burndowns actually show, four patterns to read at a glance, and when to ignore the chart and look at cumulative flow instead.
ReadStory-point estimation
What story points actually measure, the Fibonacci convention, and why estimates drift from reality (and what to do about it).
ReadTrack this for your team automatically
SprintFlint records cycle time per ticket, runs Monte Carlo forecasts on every sprint, and surfaces p85 in dashboards. The toolkit, but built into your sprint workflow.