{"id":3083,"date":"2025-06-19T09:00:00","date_gmt":"2025-06-19T07:00:00","guid":{"rendered":"https:\/\/getnave.com\/blog\/?p=3083"},"modified":"2025-06-17T13:51:55","modified_gmt":"2025-06-17T11:51:55","slug":"story-points-to-hours","status":"publish","type":"post","link":"https:\/\/getnave.com\/blog\/story-points-to-hours\/","title":{"rendered":"Why Your Delivery Predictions Will Always Be Wrong if You Keep Mapping Story Points to Hours"},"content":{"rendered":"
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When it comes to making delivery commitments, mapping story points to hours to estimate your work is a terrible piece of advice. In fact, there is a very simple exercise that can be used to reveal this paradox.<\/p>\n

Bar Vaccin (Haute Cookure) is a small cozy place in Oostmalle, Flanders, here in Belgium. For those of you who have stuck around for a while, you already know that apart from heavyweight boxing, I\u2019m also addicted to French cuisine. Bar Vaccin is a wonderful Michelin star restaurant and even if it wasn\u2019t located only 10 km away from our house, I\u2019d still always go back for our birthdays, anniversaries, and any other special occasions we celebrate. Over time, it also has become my favorite place to meet with potential customers who are looking to adopt Nave within their organization.<\/p>\n

The last time I went there was a few months ago, just before pandemic precautions required the place to close, and I met with the technical director of a big media company. With a glass of Vaccin\u2019s famous namesake cocktail, we were talking about their main problem – lack of predictability.<\/p>\n

There was something that she said which particularly struck me: \u201cWhen we meet with the teams and they say this story is 2 story points, I do the math in my mind (1 point is approx. 3 days) and I know right away it will take 6 days. If they say, the story is 8 points, that would translate to about 3 weeks. However, I don\u2019t understand why this approach always ends up wrong!\u201d.<\/p>\n

Well, let\u2019s dig deeper into it!<\/p>\n

Compare Story Points of Completed Stories With Their Cycle Time<\/h2>\n

Before we begin, let\u2019s clarify that when we talk about cycle time<\/a>, we are talking about the amount of elapsed time between the moment a work item starts and when it finishes.<\/p>\n

\"Kanban<\/a><\/p>\n

Let\u2019s do an exercise. Let’s build a scatterplot with story points on the X-axis and cycle time on the Y-axis. We\u2019ll define 1, 2, 3, 5, and 8 points on the X-axis (you can adjust these values based on your own context). Now, let\u2019s plot how many days have taken for a story assigned with 3 story points to be completed. In this example, that story needed 12 days to be finished.<\/p>\n

\"Story<\/a><\/p>\n

Now, let\u2019s map story points to hours for the last 20 to 30 completed stories. For each work item, add the story points to column B in the \u201cStory points to hours correlation\u201d spreadsheet and then add the actual cycle time it has taken to complete the item to column C.<\/p>\n

Moving on, we would expect that items with 1 story point will be relatively quick to complete and as the story point value goes up, the time that an item has taken will slightly increase.<\/p>\n

This is what the correlation between story points and cycle times looks like for one of the media company development teams we talked about in bar Vaccin:<\/p>\n

\"Story<\/a><\/p>\n

If you look into the cycle times perspective, the items with 1 story point can range from anything between 1 day all the way up to 22 days. The same results are observed for items with 2 story points and 3 story points. The most surprising trend is that their 8 point stories are in the same date range as the items with 1 story point.<\/p>\n

Use the \u201cStory points to hours correlation\u201d spreadsheet to map your own data and visualize whether or not there is a correlation between story points estimation and the actual time required to complete your work.<\/strong> The main purpose of the chart is to serve as evidence to prove that story points should not be mapped to hours. Doing this exercise is supposed to be a one-time effort, the results of which would hopefully call this vicious practice into question. Providing proof based on your historical performance is the best approach to communicating the fact that converting story points into hours will land you in hot water.<\/p>\n

If you haven\u2019t registered for Nave yet, you can do it here<\/a> \u2192<\/p>\n

It\u2019s free for 14 days, no CC required! It will take just a couple of minutes to come up with a reliable delivery forecast.<\/p>\n