Opening hours versus plot points in Scrum

Question

Is there a strict relationship between task hours and history points? If a story with a storyline of 10 takes 100 hours, should a story with 15 points take about 150 hours? If not, then what other factors distinguish them?

Answer 1

We use points as an estimate, so we can calculate the duration based on current knowledge. Recent experience may show that during a 3-week sprint, they can provide creative and clean work of 20 points. After the change, to improve quality, our next sprint may show 15 points for a 3-week sprint. With both of them, we can use the remaining points of history to create a forecast based on current knowledge, rather than stick to the knowledge of our initial assessment.

So yes, there are relationships, but they change based on empirical data. Relative size estimates allow us to constantly plan for duration estimates to require a complete reevaluation to accommodate new knowledge.

Answer 2

No no.

It is perfectly normal to have two user stories that have the same Story Point rating, and yet have different task ratings or actual efforts. The difference does not have to be huge, but it will exist.

The real beauty of Story Points is that they are an abstraction that makes high-level assessment quick and easy.

Answer 3

Definitely not. There is a very large non-linearity in the assessment: we can much better evaluate small problems than large ones. Worse still, the fallacy in evaluating software: if you can make a good assessment, too much of the work is repeated, not new, and needs to be automated.

Answer 4

Here is a link to Why use dots instead of hours and provides a good breakdown of information.

https://pm.stackexchange.com/questions/2765/agile-why-use-points-instead-of-hours

Answer 5

In addition, glasses are a reflection of perceived risk or difficulty in history. A 20-point story is not only 4 times larger than a 5-point story. It also reflects the team's uncertainty in the true size of the story. The further you move, the worse it gets.