In the Scrum framework, estimation is a common practice, yet it remains largely an optional one. Unlike other frameworks that outline specific estimation techniques, the Scrum Guide itself doesn’t prescribe any particular method—or even explicitly require teams to estimate their work. This flexibility allows Scrum teams to tailor their estimation processes to best fit their unique needs and workflows.
In this article, we’ll explore why Scrum teams often choose to estimate, how it aligns with Scrum principles, and some commonly used estimation techniques that can help your team plan work efficiently and realistically within each Sprint.
Why Does Estimation Matter in Scrum?
Scrum prioritizes adaptability and responsiveness, enabling teams to deliver value continuously and refine their approach based on real-time feedback. So, why do so many Scrum teams incorporate estimation if it’s not mandated by the Scrum Guide?
1. Better Sprint Planning
Estimation helps teams assess the scope of work for each Sprint. By gauging the complexity or effort required for Product Backlog Items (PBIs), teams can better understand what they can realistically achieve within a Sprint’s timeframe.
2. Enhanced Transparency and Predictability
When a team estimates PBIs, it becomes easier to gauge the team’s capacity over time. This predictability is particularly valuable for stakeholders, helping to set expectations and build trust through a more consistent flow of completed work.
3. Supports Continuous Improvement
Through estimation, teams can identify discrepancies between their planned and actual progress. This comparison encourages retrospectives, allowing teams to reflect on their workflows and find ways to improve their estimates over time, making future Sprints even more efficient.
The Scrum Guide on Estimation: What Does It Say?
Interestingly, the Scrum Guide makes very limited mention of estimation. The Guide only states that higher-priority PBIs should be “sized” so they can be completed within one Sprint. However, it doesn’t specify how teams should size these items or even require them to use specific estimation methods.
For many teams, this flexibility is empowering. It allows teams to choose or even create their own estimation techniques, adapting to their needs rather than adhering to a one-size-fits-all approach.
Popular Estimation Techniques in Scrum
While the Scrum Guide may not enforce any estimation methods, there are several widely adopted techniques that can support teams in managing their workloads effectively. Here are some of the most popular estimation practices:
1. Planning Poker
Planning Poker is a collaborative estimation technique where team members assign points to PBIs based on complexity or effort. Using cards with a modified Fibonacci sequence (e.g., 1, 2, 3, 5, 8, etc.), each team member privately selects a card to represent their estimate. All cards are revealed simultaneously, and any significant discrepancies are discussed before a consensus is reached. This method not only provides an accurate estimate but also fosters team alignment and understanding.
2. T-shirt Sizing
T-shirt sizing uses broad categories (XS, S, M, L, XL) to classify PBIs by size or effort level. This method is particularly helpful for teams needing a quick, high-level estimation approach. By avoiding numerical estimates, it minimizes over-precision, focusing on relative complexity rather than exact metrics.
3. The Bucket System
The Bucket System is useful for teams estimating multiple PBIs at once. Items are categorized into “buckets,” each representing a specific level of effort or complexity. Team members sort PBIs into these buckets, which can be refined through discussion. This technique is well-suited for larger teams needing efficient batch estimations.
4. Affinity Estimation
Affinity Estimation is a technique where team members group PBIs by similarity in complexity or effort, using a scale from least to most complex. It’s a visual method that can work well in conjunction with physical or digital boards, encouraging quick yet effective team alignment on workload estimations.
When to Skip Estimation
While estimation can be a powerful tool, it’s not always necessary for every team. Experienced teams with a deep understanding of their capacity may find that estimation adds little value. Additionally, some teams prioritize a Kanban-style flow within Scrum, focusing more on cycle times and continuous delivery than on estimating each Sprint’s workload.
Conclusion: Estimation as a Choice, Not a Requirement
Scrum is designed to be flexible, and estimation is one of many practices that teams can adapt—or even forgo—as they see fit. While estimation can offer valuable insights for planning and transparency, it’s ultimately a tool to support your team’s goals and improve Sprint efficiency. If your team finds estimation beneficial, experiment with different methods until you find what works best for your workflow. However, if estimation seems cumbersome or adds little value, remember that it’s entirely optional within Scrum.
If you are interested in staying up-to-date with technical product ownership and management, coaching and training, and gaining insights from a agile professional.
--> Bookmark this website, Subscribe on the "continuous learning updates and Connect with me on LinkedIn.
