When to use it
Use consistent size measures and calibrated historical relationships for the decision at hand.
When to be cautious
Do not treat story points as universal hours or reproduce a licensed counting manual as a free substitute.
Apply it
- Choose a size or effort measure and define its boundary.
- Estimate with people who understand the work and compare similar completed items.
- Use actual delivery evidence to improve the forecast.
An example in practice
A team revises its release forecast using completed comparable backlog items rather than translating another team’s points into days.
Source & credit
Standard estimating practice; the cited guide documents use rather than claiming invention.
GAO: Cost Estimating and Assessment Guide
This explanation and example are independently written. The source is a reading reference; linking it does not grant permission to reuse its text, figures or assessments.