Agile Estimation Techniques | David Tzemach

There are several different techniques to conduct the estimation process. This article will describe those techniques, their relevance, and how practical they are in Agile projects.

Traditional Estimations (Days/Hours)

Traditional estimations are based on units of Days or Hours (In rare cases, I saw it even used to estimate stories based on 20, 30 and 45 minutes), and the team uses them to estimate their stories and tasks. In my opinion, this is fine if it assists the team in the transition process and even if they want to embrace it as their estimation technique. I hope that you are not heeding the tales about traditional estimations not being suitable for Agile as they are rarely accurate for all of you who think otherwise.

T-Shirt Size

T-shirt size is a great estimation technique I use in organizations at the beginning of the transformation. You cannot use story points with some teams as team members align story points to hours of effort. This leads to further confusion.

T-shirt size allows teams to overcome this problem as this estimation technique is non-numeric. It will enable Agile teams to work with something easier to relate to. It removes the implied precision of a numerical value, and it frees the team to think abstractly regarding the effort they need to invest in each story.

The basic process of this technique is relatively simple to use:

1. A set of cards representing a specific size are distributed horizontally on a table. The sizes are divided into Extra Small (XS), Small (S), Medium (M), Large (L) and Extra Large (XL).

2. The team adds each user story under the appropriate size card.

3. Once all stories are sorted based on a collaborative discussion, the team approves their selection or has another cycle of a debate on stories with high uncertainty.

Dot Voting

Dot voting is another relative estimation technique. It allows Agile teams to vote their preferences among a set of items by simply placing dots on items (e.g., features, stories, impediments, etc.) they believe should have a higher priority than other items. The number of dots determines the priority level. The more dots, the higher the priority of the item.

Dot voting is a very effective estimation technique because it allows all team members to affect the priority of items equally. All team members have an equal number of votes (represented as dots), which they can spread among items as part of the estimation process.

For example, the team identified a list of eight items in the retrospective meeting. They must now narrow the list to the highest value items. To do this, each team member receives an equal number of dots (range of 3-5) to vote on the items.

Note: They can put all dots on one item or spread them between different items.

The high-level process of using this estimation technique includes the following phases:

Phase 1: Facilitation, review, and voting

1. All items are placed in an accessible location to enable team members to vote.

2. All items are reviewed and understood by all stakeholders.

3. Each team member receives an equal number of dots (I usually use five points.).

4. Each team member is requested to place their votes; each one of the members places dots on each item based on their judgment.

5. Once the estimation process is completed, items are ordered from most dots to least.

6. Approve with the team the outcome of the vote.

Phase 2: Adjustments and re-voting (optional)

If the team are not completely happy with the outcome (as often happens...), you should follow the following steps to optimize the output:

1. Arrange items into three groups to represent low, medium and high priorities.

2. Review with the team the stories in each group.

3. Initiate a new vote cycle for all items with the highest priority.