Why Do We Use Story Points Estimating?

In the realm of software development, agility is crucial to success. Agile methodologies have revolutionized the way teams collaborate and deliver value to customers. One crucial aspect of agile development is estimation, and story points have emerged as a popular and effective method for estimating the effort required for tasks.

In this article, we delve into the reasons behind the widespread adoption of story points estimating, exploring its benefits, challenges, importance, and the artistry that goes into the process.

What are Story Points? 

Before delving into why story points are used, it's essential to understand what they are. Story points are a measuring unit for expressing the overall size or complexity of a user story or task in software development. Unlike traditional time-based estimates (hours or days), story points are a relative measure, providing a high-level assessment of the work involved.

Read more about: what are story points in agile

The Agile Manifesto Influence

Story points align with the principles of the Agile Manifesto which emphasizes on individuals and interactions above processes and tools. The Agile Manifesto encourages adapting to change, fostering collaboration, and delivering working software frequently. Story points, being a collaborative and adaptable estimation technique, resonate well with the Agile mindset.

Does Using Story Points Matter? 

Absolutely. Employing story points is crucial for the following reasons:

1. Predicting Completion: Story points offer a reliable method for predicting task completion. While precision is often desired, it can be more costly to achieve. In contrast, story points provide sufficient accuracy, especially in nondeterministic systems. Time alone doesn't directly correlate with progress, but understanding the rate of effort resolution allows for a more accurate forecast of completion.

2. Distinguishing Accuracy from Precision: Recognizing the difference between accuracy and precision is vital. While precision is more expensive, accuracy generates more value. Story points strike a balance, offering adequate accuracy without the added costs associated with high precision. In the context of unpredictable systems, story points prove to be a pragmatic and effective estimation tool.

3. Velocity Enhances Predictability: The stability of story point estimates is reinforced by velocity, contributing to increased predictability. The ultimate goal of creating estimates is to establish a level of certainty about the progression of tasks. By stabilizing story point estimates, teams gain a clearer and more reliable understanding of the time required for task completion.

4. Focus on Sprint Capacity, Not Individual User Story Duration: In the context of fixed-length sprints, understanding the duration of individual user stories may not be critical. Instead, the emphasis should be on determining how many story points can be accommodated within a sprint. This approach aligns with the agile philosophy and enhances the team's ability to plan and execute tasks efficiently within the confines of a sprint.

Gain more insights: What is a User Story?

How To Calculate Story Points In Agile? 

Story points in Agile measure the effort needed for any user story or product backlog item, equating effort to time required for completion. Factors like work volume, task complexity, and associated risks influence this estimation.

When using story points, elements such as complexity, effort, risk, and volume shape the determination of these points. At its core, story points signify an effort estimate. Let's explore how factors affect the effort estimate through examples.

1. Work Volume: The quantity of work directly impacts the story point estimate. For instance, developing two web pages—one with a single field and another with 100 fields—illustrates this. While the second page may not be inherently more complex, its higher volume justifies a higher story points estimate

2. Risk and Uncertainty: The level of risk and uncertainty tied to a backlog item influences the story point estimate. If a stakeholder is unclear about requirements, that ambiguity affects the estimate. Similarly, modifying old, fragile code without automated tests raises inherent risks, contributing to the story point estimate. 

3. Complexity: Complexity is crucial in determining the story point estimate. Comparing two screens, one with 100 simple text fields and another with varied complexities like date pickers and interactive fields demonstrates this. Despite having the same field count, the complex screen demands more implementation time, considering potential mistakes and corrections. 

Story points in Agile provide a nuanced estimate, considering work volume, risk, and complexity. This comprehensive approach aids effective project planning in the dynamic landscape of software development.

The Advantages of Story Points Estimation

1. Relative Sizing

Story points focus on relative sizing rather than absolute time estimates. This allows teams to compare the complexity of tasks without the need for precise time calculations. It promotes a more realistic and less time-consuming approach to estimation.

2. Fostering Collaboration

Story points estimation involves the entire team, encouraging collective decision-making. Team members bring diverse perspectives to the table, leading to richer discussions about the complexity and potential challenges associated with a task. This collaborative approach builds a shared understanding among team members.

3. Mitigating Individual Bias

Estimating in story points helps mitigate the influence of individual biases. When estimating in hours, team members might be inclined to provide optimistic or pessimistic estimates based on personal work habits. Story points, being a more abstract measure, reduce the impact of individual biases and encourage a more objective assessment.

4. Adaptability to Change

Agile development thrives on its ability to adapt to changing requirements. Story points are inherently flexible, allowing teams to adjust estimates as they gain more insights during the development process. This adaptability helps teams respond to changing priorities and uncertainties in project requirements.

5. Focus on Complexity

Story points emphasize the inherent complexity of a task rather than the time it takes to complete. This shift in focus encourages teams to think holistically about the challenges involved, considering factors such as dependencies, unknowns, and technical debt.

The Art and Science of Story Points Estimation

1. Planning Poker

Planning Poker technique is a widely used technique for story points estimation. Team members collectively discuss a user story, and each participant privately selects a story point value based on their understanding. The team then reveals their estimates simultaneously, fostering discussion and convergence toward a consensus.

Discover more: What is Planning Poker in Agile?

2. Fibonacci Sequence

Often, Story points are assigned using the Fibonacci sequence (1, 2, 3, 5, 8, 13, etc.). This sequence reflects the uncertainty and imprecision inherent in estimating larger tasks. Using Fibonacci numbers acknowledges that the precision of estimates diminishes as the scope of work increases.

3. Velocity Tracking

Velocity is an essential metric in agile development, representing the amount of work a team can complete in a given time frame. By tracking velocity over multiple sprints, teams can refine their story points estimation process and improve accuracy over time.

Challenges and Considerations

1. Learning Curve

Adopting story points estimation may pose a learning curve for teams accustomed to traditional time-based estimates. It requires a shift in mindset and ongoing practice to master the art of relative sizing.

2. Consistency Across Teams

Achieving consistency in story points estimation can be challenging, especially in large organizations with multiple teams. Variability in estimation practices across teams can hinder accurate portfolio-level planning.

3. External Stakeholder Expectations

External stakeholders, such as project sponsors and clients, may be more accustomed to traditional time-based estimates. Communicating the value of story points and managing expectations becomes crucial to maintaining trust.

Lastly!

Story points estimation has become a cornerstone in agile development due to its alignment with Agile principles and its ability to foster collaboration, adaptability, and a focus on complexity. By embracing the art and science of story points estimation, teams can navigate the uncertainties of software development more effectively, delivering value to customers in a dynamic and ever-changing landscape. As the agile community continues to evolve, the use of story points remains a testament to the industry's commitment to continuous improvement and innovation.