Planning Poker - Agile Estimation Method

Planning Poker is a consensus-based technique for estimation, mostly used to estimate effort or relative size of development goals in software product development. Planning Poker is done with story points, ideal days, or any other estimating units. The Scrum Master, Product Owner, and the development team participate in Planning Poker activity.

Purpose: Estimate the effort for User Stories (Product Backlog Items, Value Drivers)

Prerequisites: All items have a value estimate. A separate note card is written for each story. Full team membership is known and available for planning, and each team member has a set of planning game cards. The team members are provided with a deck of playing cards. These cards are numbered in Fibonacci sequence (0, 1, 2, 3, 5, 8, 13, 21, …) or a modified Fibonacci sequence like 0, 1/2, 1, 2, 3, 5, 8, 13, 20, 40, 100, ?, α. The last 2 symbols denote ‘not sure’ or ‘too complicated to estimate’. The beauty of using the Fibonacci sequence is that the ratio between two successive numbers in the sequence is constant at 1.6 ( 8/5 = 1.6, 34/21 = 1.6, 55/34=1.6 and so on) and so naturally represents an increasing difficulty at estimating the size of a work item as it grows larger and larger.

Card(s)	Interpretation
0	Task is already completed.
1/2	The task is tiny.
1, 2, 3	These are used for small tasks.
5, 8, 13	These are used for medium sized tasks.
20, 40	These are used for large tasks.
100	These are used for very large tasks.
<infinity>	The task is huge.
?	No idea how long it takes to complete this task.
<cup of coffee>	I am hungry 🙂 or Need a Break

Agile Planning Poker Rules

The rules for playing Planning Poker activity are as follows.

The PO selects a PBI which needs to be estimated and reads that to the team. e.g. The Product Owner picks prioritized items from the backlog.
The development team members carry out a discussion on the selected item and ask pertinent questions to the PO. e.g. PO clarifies requirements, assumptions and risks
Each team member secretly picks up one card to represent his/her estimate.
Once all the estimations are done, these are exposed to all the team members.
If everyone selects the same card, they do consensus, and that number becomes the PBI estimate.
If the estimates are not equal, the estimators have a discussion to come to a common justification. Or else, the high-low story points estimators are asked to explain their estimates.
After the discussion, they go back to step 4 and repeat till the consensus is reached.
After playing 2 or 3 rounds, the estimates are expected to converge or be within an acceptable range. If it does not, then the moderator could go with the majority, mean or a weighted average of the estimates.
The Scrum Master acts as the moderator and chairs the meeting. Coaches and helps the team in carrying out the activity in a better way. e.g. SM continually searches for individuals who, by their body language or by their quietness, appear to disagree and helps them engage better.

Key points of Agile Planning Poker

It is extremely important that the voting for an item continues until all team members unanimously vote the same way (this way team members and outside stakeholders cannot blame any individual for “wrong” estimates)
In Scrum, it is normal for the Product Owner to be present during this process, but not to participate in the voting
Voting should not include extensive discussion – instead, the emphasis is on multiple rapid voting cycles
If more than one person has the lowest or highest vote, usually just one person shares their reason in order to help the process move quickly.
The first few items will often take 10 or 15 rounds of voting before the team arrives at a unanimous vote.
Later on, items may take just one or two rounds of voting to arrive at a unanimous decision
Some teams, where trust levels are high, will discard with the use of physical cards and just briefly discuss votes

Benefits of Agile Planning Poker

Fosters collaboration by engaging entire team.
Creates consensus estimate rather than having a single person driving the estimate.
Exposes issues early through discussion of each user story.

Planning poker combines three methods of estimation −

Expert Opinion − In expert opinion-based estimation approach, an expert is asked how long something will take or how big it will be. The expert provides an estimate relying on his or her experience or intuition or gut feel. Expert Opinion Estimation usually doesn’t take much time and is more accurate compared to some of the analytical methods.

Analogy − Analogy estimation uses comparison of user stories. The user story under estimation is compared with similar user stories implemented earlier, giving accurate results as the estimation is based on proven data.

Disaggregation − Disaggregation estimation is done by splitting a user story into smaller, easier-to-estimate user stories. The user stories to be included in a sprint are normally in the range of two to five days to develop. Hence, the user stories that possibly take longer duration need to be split into smaller use-Cases. This approach also ensures that there would be many stories that are comparable.

When should we engage in Planning Poker?

Most teams will hold a Planning Poker session shortly after an initial product backlog is written. This session (which may be spread over multiple days) is used to create initial estimates useful in scoping or sizing the project.

Because product backlog items (usually in the form of user stories) will continue to be added throughout the project, most teams will find it helpful to conduct subsequent agile estimating and planning sessions once per iteration. Usually, this is done a few days before the end of the iteration and immediately following a daily standup, since the whole team is together at that time anyway.

How does poker planning work with a distributed team?

PlanningPoker.com. Mountain Goat Software helped develop that website to offer it as a free resource to the agile community. A product owner, ScrumMaster or agile coach can log in and preload a set of items to be estimated. A private URL can then be shared with estimators who log in and join a conference call or Skype session. Agile estimating and planning then proceeds as it would in person.

Tips for Agile Planning Poker in Scrum

Keep discussions productive: Consider purchasing a two-minute sand timer, and allowing anyone in the meeting to start it at any time. When the sand runs out, the next round of Planning Poker cards is played. This helps teams learn to estimate more rapidly within agile planning.
Break out into smaller sessions: It is possible to play Planning Poker with a subset of the team. It’s not ideal, but a good option if there are many stories to be estimated, as can often happen at the start of a new project.
Choose the right time to play: Estimating teams will need to play Planning Poker at two different occasions. The first time, teams will usually estimate a large number of items before the project kicks off or during first iterations. The second time, teams need to put forth ongoing effort to estimate new stories identified during an iteration.