How to Estimate the Effort of Backlog Items With Points Using Planning Poker and Magic Estimation
Roland Wanner
Lean Portfolio Manager | Senior PMO | Successful Author | SAFe 6.0 Certified
The effort of backlog items in Scrum should be estimated so that a Scrum team knows how many of them it can implement in the next Sprint. The developers estimate the effort in the estimation meeting. This can be done with different methods. In this article I will show you how to estimate with points and you will learn one of the most popular estimation methods in agile projects, Planning Poker and one of the most efficient methods, Magic Estimation. Take the next step and deepen your knowledge!
How to Estimate with Points
In the article?How to Estimate the Effort for Product Backlog Items in Scrum?you learned how to conduct an estimation meeting. The most important activity in it, is of course, to estimate the effort of each backlog item, only then you know how many of them you can implement in the next sprint.
In contrast to traditional estimation methods, agile methods do not estimate the effort of a user story in “line of codes”, but mostly use points (story points).
Working with points is very easy. First, a scale of points is defined with which an estimate is to be made. A non-linear scale, which corresponds approximately to a Fibonacci function, has proven itself in this context. This means that the larger the estimate, the greater the distance between the estimates. Here you see what this scale looks like:
1,2,3 . 5 . . 8 . . . 13 . . . . . .20 . . . . . . . . . . . . 40 . . . . . . . . . . . . . 100
If you estimate requirements with points, you always estimate the effort relative to another requirement. This means that at the beginning you will estimate a small requirement from the Product Backlog, which you know how to implement. Then, you estimate another requirement in relation to the first estimate. Once you have estimated more than two requirements, compare the new requirements with existing estimates for further estimates. This ensures that the estimates are relative to each other.
Especially if you value requirements as “very large” (e.g., “40”), it may make sense to go into more detail and break them down into separate user stories to get a more accurate estimate.
The quality of the estimates will of course improve if the Developers understand the requirements well and know the necessary work steps for the implementation.
In the next sections, I will show you two estimation methods with which you can efficiently carry out the estimation process.
Planning Poker
Planning Poker??was first used and named by James Grenning in 2002 and later made popular by Mike Cohn in the book?Agile Estimating and Planning. Planning Poker??is a fun way to conduct the Estimation Meeting efficiently.
At the beginning, each participant gets a stack of Planning Poker??cards with values from 0 to 100. The values correspond to the non-linear scale of a Fibonacci series of numbers that you already know. Then, the Product Owner presents a user story from the Product Backlog. The team will clarify any ambiguities with the Product Owner. Then, the team discusses the steps that are necessary to implement the user story. Then, each team member selects the card from their stack of Planning Poker??cards that best suits the effort of the User Story and places it face-down on the table.
At the same time, all team members turn their cards around. If the card values are very different, the team members who are furthest apart explain why they have chosen their value. After that, an estimate is made again after the same procedure. Estimates will often converge in the second round. If this is not the case, repeat the process until the team has agreed on an estimate. It rarely takes more than three rounds to reach the goal.
If the Scrum Team doesn’t know about Planning Poker??yet, the process will still be quite slow. But as soon as a few rounds are played, it gets faster. If you want to make planning poker efficient, use a 2-minute hourglass timer for each round of poker.
The moderator takes notes during the Planning Poker??session that can be helpful when programming and testing the user story?(Cohn, 2017).
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Magic Estimation
If you need to estimate 50 or 100 user stories, Planning Poker is too slow. That’s why more and more Scrum Teams are using *Magic Estimation”, a method Boris Gloger adopted and refined from Lowell Lindstrom.
For Magic Estimation you will need a set of Planning Poker??cards, the floor or a large table and the user stories from the Product Backlog prepared by the Product Owner. The cards with the user stories should be written as large as possible so that they can be read by larger groups even from a greater distance.
The Product Owner places the Planning Poker cards in a row of numbers on the table or the floor, separated by distances corresponding to the proportions:
1,2,3 . 5 . . 8 . . . 13 . . . . . .20 . . . . . . . . . . . . 40 . . . . . . . . . . . . . 100
There is one important rule in Magic Estimation: Do not speak during the performance!
How to Perform Magic Estimation
When Using Magic Estimation and Planning Poker?
Many teams will have a planning poker session or magic estimation for the first time in the estimation meeting shortly after an initial Product Backlog has been created. The purpose of this session is to provide initial estimates that are useful for sizing the project and release planning.
Effort estimation with Planning Poker or Magic Estimation are regularly carried out during the entire project duration. This is because new backlog items are constantly being added or existing ones are constantly changing. The best time for this is the Estimation Meeting just before the end of the Sprint.
Effort estimation with distributed teams is somewhat more complex. There are some free online tools, for example for Planning Poker?. You will find these on:?https://www.planningpoker.com/
Here You Can Find More Knowledge
This was an overview about how to estimate the effort of Backlog Items with points using Planning Poker and Magic Estimation.?What is your experience with two methods??Do you agree with my statements in this article or do you have a different opinion? Share your experience with the readers in the comment box below so we can all get a broader view. Thank you!
Would you like to learn more about how to make your projects more successful with Scrum and Agile Project Management??My book?Scrum – How to Successfully Apply Agile Project Management and Scrum?takes you an important step further!
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