3 techniques to perform an accurate Agile estimate
Estimation is essential in any kind of project. It is especially the case when working in Scrum mode.
A precise estimation will enable the team to:
- evaluate what to deliver during the next sprint
- prioritize the backlog correctly
When your team is trying to estimate the backlog’s content, the assessment of the task’s complexity is to prioritize over the time needed.
The three techniques below can help in this evaluation:
- Relative mass valuation
- T-shirt sizing
- Poker planning
Let us start with relative mass valuation. It consists in classifying the user stories from the smallest to the biggest. Then, you start giving weight to the stories, beginning with the smaller ones. 1 is the minimum weight, and is given to the smallest story and everything that follows until you reach a story twice as complicated as the first one, to which you give a weight of 2. This method enables the team to make a rough estimation of a large story set quickly.
T-shirt sizing consists in asking the team whether a story is XS, S, M, L, XL or XXL. It allows the team to evaluate the story in a more abstract way, without the temptation to translate points into hours of work: this is useful with a relatively inexperienced team. A drawback of this technique is the estimation’s lack of precision. Ultimately, the non-numerical values translate into numerical ones. For more fun, switch from T-shirt size to dog breed: a golden retriever weighs less than a big dane, for instance.
Poker planning is the most common way to estimate in Agile, although not the easiest. The principle is to have all team members try to estimate each story. Each team member has a set of cards following the Fibonacci sequence, and each story is read aloud. Everyone then shows the card corresponding to the effort level needed to complete the story.
Of course, these techniques require having an idea of the team’s velocity, which means the amount of complexity the team can reach per sprint. At the project’s beginning, teams will need to adapt. But within the next sprints, teams will improve remarkably.
As Agile focuses on features, you have to be attentive to quality. Do not forget to remind the team that estimates include design and documentation; this seems obvious but a reminder is sometimes useful.