Affinity Estimation vs. Planning Poker – Let's Explore

Affinity Estimation and Planning Poker are both effective techniques to estimate user stories. Follow this article to learn the working principles, use cases, and other comparison elements of both these techniques.

Organizations across the globe are today using Agile methods and techniques in their project development cycles. Agile helps organizations set a customer-oriented, feedback-driven, and iterative development model that leads to faster release and better-quality products. Agile-based development involves many stages, but the specific one we are going to discuss in this article is the estimation of product backlog items.

A product backlog is a prioritized list of features, enhancements, requirements, and defects that are to be addressed in upcoming iterations. An agile team must estimate the product backlog to have a better understanding of the lined-up work and the efforts required to complete the work. There are many estimation techniques available today to estimate product backlog. Different organizations use different techniques depending on what suits their business model. However, Affinity Estimation and Planning Poker are two of the leading estimation techniques used by many organizations. So, let's explore more about both these estimation techniques and see which one promises more accurate estimates.

Affinity Estimation – A Detailed Overview

Affinity Estimation technique is used by organizations to easily and quickly estimate a large set of user stories in story points. User stories are the way requirements are explained in a bounded context along with their acceptance criteria. Through Affinity Estimation technique, user stories are arranged based on their relative size, which means size in comparison to others.

Take three user stories as an example, i.e., X, Y, and Z. The user story Z is the largest, while the user story X is the smallest. When the team estimates those user stories using the Affinity Estimation technique, it will pick one user story, let's say Y, and places it on the scale. Now the team will pick story X and see if its size is large or small than Y. As story X is smaller than Y, so it is placed on the left side of the scale. Similarly, the team compares story Z with Y and then places it on the right side to reflect that it's larger than Y. This is how Affinity Estimation helps teams to estimate user stories through relative sizing.

Steps of Affinity Estimation Technique

Affinity Estimation is mainly used by small teams who want to quickly do relative sizing of user stories by first grabbing a few cards (user stories) and then moving them until all the cards are arranged relative to one another. Following are the steps involved in the Affinity Estimation technique:

1. On a horizontal scale, mark the left end as "Smallest" and the right end as "Highest".
2. Team members join the estimation session and receive cards (user stories) from the product owner.
3. Every member understands the story himself and then places the card in the expected right location on the scale without discussing it with others.
4. After all members have placed their cards on the scale, they now do collaborative editing of the scale. So, what they will do is discuss the stories with each other, including the implementation challenges around those stories. Afterward, they rearrange the scale.
5. Once the scale is all set, it's time to assign story points to every user story. So, the scale is divided into 5 sections, i.e., XS, S, M, L, and XL.
6. The team places the stories/cards beneath the right sections. Afterward, the team assigns the story point to each story such that XS stories get 1 point, S gets 2 points, M gets 3 points, L gets 5 points, and XL gets 8 points.

This is how teams implement the Affinity Estimation technique. Overall, the technique suits best when there is a large number of user stories to estimate.

Planning Poker – A Detailed Overview

Planning Poker is a gamified consensus-based agile estimation technique that uses numbered poker cards to estimate user stories. In this technique, the members join the estimation session and discuss and estimate user stories one-by-one through mutual understanding. The members are handed poker cards with values of modified Fibonacci sequence, i.e., 0, 1, 2, 3, 5, 8, 13, 20, 40, and 100 that they use to provide estimates and points to each user story.

Planning Poker is a popular estimation technique in organizations that are experienced with agile-based development. It is because it provides a more accurate and consensus-based estimation that values everyone's opinion.

Steps of Planning Poker Estimation Technique

A Planning Poker estimation session involves the product owner, scrum master, development team, and other key stakeholders. Once all the members join the session, the estimation process goes through the following steps:

1. The product owner takes one user story and reads it out to the team.
2. The members listen to the story and then start discussions around it, such as how to complete it, main challenges, dependencies, and similar other aspects.
3. After the discussion is completed, members pick the poker card that they think best represents the size of the story and then show them all at once.
4. If all members have selected the same poker card, then that value is selected as the team's size for that user story. If there is a big difference, then members who have given the highest and lowest values are allowed to present their reasons behind those values. After the second round of discussion, the team then re-estimates to reach the final team's estimate.
5. The team continues to follow the above 4 steps until all stories are estimated.

This way, agile teams can estimate their product backlog items using the consensus-based approach of Planning Poker. One thing you might notice with Planning Poker is that it values everyone's opinion, giving all members the chance to speak and contribute to reaching the team's estimate.

Affinity Estimation vs. Planning Poker

Affinity Estimation and Planning Poker are both useful in estimating product backlog items. However, the scenarios where they are used vary. Affinity Estimation is used by small agile teams when they want to estimate a large number of user stories with less discussion and faster estimates. Moreover, if the project is just beginning and the backlog is not estimated, then Affinity Estimation suits the situation. Similarly, if the team is working on scheduling a release, then again Affinity Estimation can serve the purpose effectively.

On the other hand, Planning Poker is used in smaller projects where the team wants to reach a common agreement on estimates. It is a gamified, fun-based estimation technique that gives a chance to every member to speak up. It can turn into an intensive debate if the members don't pick the same value, thereby resulting in mutual understanding, better estimates, and more commitment to the project.

Some of the other comparison elements of Affinity Estimation vs Planning Poker are presented in below table:

Affinity Estimation	Planning Poker
It is a fast and simple technique.	It is an easy-to-use technique but can take time to reach a consensus.
It involves less discussion on each story and the estimates are based on comparison with other stories.	Every story is discussed thoroughly before estimation without comparing it with other stories.
It does not encourage every team to speak.	It encourages everyone to speak.
It does not result in a mutual understanding of user stories.	It results in a mutual understanding of user stories.
Team members start with individual sizing of the stories, so the collaboration is not that effective.	Every estimate is based on the team's mutual understanding, thereby resulting in effective collaboration.
It is driven by the scrum master.	It is driven by the product owner.
It is recommended for early stage estimation for a large number of user stories.	It is recommended for small projects where a thorough understanding of user stories is needed before estimating.
It is suited for new agile teams.	It is suited for both new and experienced agile teams.

Since the Planning Poker technique involves a thorough discussion of every user story before estimation and the estimates are also consensus-based, therefore it results in more accurate estimates compared to Affinity Estimation. But Planning Poker takes more time compared to Affinity Estimation, so it is best suited for small projects.

Today, the accuracy of the Planning Poker technique has made it stand as one of the most popular estimation techniques used by hundreds of thousands of organizations. In fact, organizations with a remote workforce or who don't want to spend much time in estimation sessions are using the modified Planning Poker technique known as Asynchronous Poker or Async Poker. In this approach, team members provide estimates remotely and participate in a brief discussion session to reach the team's consensus.

Wrapping Up – Which Technique is the Best?

After going through the basic principles and working steps of both Affinity Estimation and Planning Poker techniques, you must have realized that they both can estimate the product backlog items effectively. However, both have their specific use cases, which does not make anyone a winner in all scenarios. If there are a large number of user stories and the project is just beginning, then Affinity Estimation serves the job effectively. However, if the project scale is small, user stories are few in number, and there is a need for more accurate estimates with mutual understanding, then Planning Poker is the best choice. So, pick the technique depending on your project scenario and start estimating rightly.