Kanban T-Shirt Sizes
Contents
As software development teams strive for better estimation and planning, they often face challenges in evaluating the complexity of tasks. To address this, we can leverage the Kanban T-shirt size framework to estimate effort, complexity, uncertainty, and risk. In this article, we’ll explore the common factors that influence our work and provide a practical guide on how to apply the Kanban T-shirt size.
Sizes
To simplify the estimation process, we can use a Kanban T-shirt size framework to categorize tasks based on these four factors. The most common sizes are:
- XS (Extra Small): Effort is low, complexity is simple, uncertainty is minimal, and risk is negligible.
- S (Small): Effort is moderate, complexity is straightforward, uncertainty is limited, and risk is manageable.
- M (Medium): Effort is substantial, complexity is moderate, uncertainty is moderate, and risk is moderate.
- L (Large): Effort is high, complexity is significant, uncertainty is considerable, and risk is substantial.
- XL (Extra Large): Effort is very high, complexity is complex, uncertainty is high, and risk is high.
Factors
To accurately assess the complexity of tasks, we need to consider four key factors:
Effort
This factor focuses on the amount of work involved in completing a task. It’s essential to estimate the time required to complete the task, taking into account any necessary skills or expertise.
| T-Shirt Size | Complexity Level | Description | Example |
|---|---|---|---|
| Tiny | Low Complexity | Requires minimal understanding of the system and can be completed with basic skills. | - Restarting a service with a documented procedure (clear steps involved). |
| Small | Moderate Complexity | Involves a well-defined task with a clear understanding of the requirements, but might require some logic or integration with existing functionalities. | - Implementing a new button that triggers a specific action in the system, but requires understanding how the action interacts with other parts of the code (e.g., updating a database). |
| Medium | High Complexity | Requires some investigation and understanding of the system’s logic. May involve new functionalities or interactions with existing functionalities. | - Creating a new user interface element that interacts with different parts of the system in a new way, requiring understanding of data flow and user interactions. |
| Large | Very High Complexity | Involves significant unknowns or requires working with new technologies or complex integrations with specific requirements. | - Integrating with a third-party service with a custom API that requires in-depth understanding of the API structure and data format (unknown behavior or complex data manipulation). |
| X-Large | Extremely High Complexity | Requires extensive planning, design, and potentially involves research or innovation. May have a high degree of uncertainty or risk. | - Implementing a new recommendation system that personalizes content for each user. This involves complex algorithms, data analysis, and user interface design considerations (unfamiliar technology and innovative approach). |
Complexity
This factor focuses on the level of understanding and investigation needed to complete a task. Tasks with higher complexity levels may require more research, analysis, or creative problem-solving.
| T-Shirt Size (Uncertainty) | Description | Example |
|---|---|---|
| Tiny (Low Uncertainty) | Clear understanding of the task and requirements. Minimal risk of unexpected issues. | - Fixing a typo with a well-defined solution and a documented approach. |
| Small (Moderate Uncertainty) | The task is well-defined, but there might be minor unknowns about data formats or edge cases. | - Implementing a new button with a clear function, but unsure of the exact wording for the button label based on user interface design preferences. A/B testing can help determine the best option with minimal impact. |
| Medium (High Uncertainty) | There are unknowns about the specific user needs or how a feature will be used, but the core functionality is clear. | - Creating a new report based on existing data, but unsure of exactly which data points are most relevant to users. User research might be needed to refine the report format and content. |
| Large (Very High Uncertainty) | Significant unknowns about the task, potentially involving new technologies or external dependencies. High risk of encountering unforeseen challenges. | - Developing a new functionality using a cutting-edge technology that the team has no prior experience with. There could be unforeseen challenges with integrating the new technology or limitations in its capabilities. |
| X-Large (Extremely High Uncertainty) | The task involves significant unknowns or requires innovation with limited understanding of the potential challenges. High degree of risk and potential for project pivots. | - Implementing a completely new business model that relies on user behavior and market adoption, with limited industry examples. There’s a high chance of needing to adapt the approach based on user feedback and market response. |
Uncertainty
This factor focuses on the unknowns and potential surprises that might arise during a task. Uncertainty can stem from unclear requirements, changing circumstances, or unpredictable dependencies.
Absolutely! Here’s a table focusing on uncertainty in T-Shirt sizing, with distinct examples from effort and complexity:
| T-Shirt Size (Uncertainty) | Description | Example |
|---|---|---|
| Tiny (Low Uncertainty) | Clear understanding of the task and requirements. Minimal risk of unexpected issues. | - Fixing a typo with a well-defined solution and a documented approach. |
| Small (Moderate Uncertainty) | The task is well-defined, but there might be minor unknowns about data formats or edge cases. | - Implementing a new button with a clear function, but unsure of the exact wording for the button label based on user interface design preferences. A/B testing can help determine the best option with minimal impact. |
| Medium (High Uncertainty) | There are unknowns about the specific user needs or how a feature will be used, but the core functionality is clear. | - Creating a new report based on existing data, but unsure of exactly which data points are most relevant to users. User research might be needed to refine the report format and content. |
| Large (Very High Uncertainty) | Significant unknowns about the task, potentially involving new technologies or external dependencies. High risk of encountering unforeseen challenges. | - Developing a new functionality using a cutting-edge technology that the team has no prior experience with. There could be unforeseen challenges with integrating the new technology or limitations in its capabilities. |
| X-Large (Extremely High Uncertainty) | The task involves significant unknowns or requires innovation with limited understanding of the potential challenges. High degree of risk and potential for project pivots. | - Implementing a completely new business model that relies on user behavior and market adoption, with limited industry examples. There’s a high chance of needing to adapt the approach based on user feedback and market response. |
Risk
This factor focuses on the potential for problems and their impact on the project. High-risk tasks may have significant consequences if not completed successfully, such as project delays, budget overruns, or even cancellation.
| T-Shirt Size (Risk) | Description | Example |
|---|---|---|
| Tiny (Low Risk) | Minimal chance of encountering problems during development. Easy to recover from any unexpected issues. | - Fixing a typo with a well-defined solution and a documented approach. |
| Small (Moderate Risk) | There’s a small possibility of minor issues arising due to data formats or edge cases. Easy to adjust and course-correct if needed. | - Implementing a new button with a clear function, but unsure of the exact wording for the button label based on user interface design preferences. A/B testing can help determine the best option with minimal impact. |
| Medium (High Risk) | There’s a chance of encountering challenges due to unclear user needs or potential limitations in the chosen approach for a feature. Requires contingency plans and potential rework. | - Creating a new report based on existing data, but unsure of exactly which data points are most relevant to users. User research might be needed to refine the report format and content, potentially causing delays. |
| Large (Very High Risk) | Significant potential for problems due to new technologies, external dependencies, or complex integrations with specific requirements. Requires mitigation strategies and potential for significant rework. | - Developing a new functionality using a cutting-edge technology that the team has no prior experience with. Issues with integrating the new technology or limitations in its capabilities could cause significant delays and require major changes. |
| X-Large (Extremely High Risk) | High likelihood of encountering unforeseen challenges due to innovation or a completely new business model. Requires strong risk management and potential for project pivots. | - Implementing a completely new business model that relies on user behavior and market adoption, with limited industry examples. The approach might not be feasible or deliver the expected value, requiring significant changes or even abandoning the project. |
Differences
The key differences here are:
- Effort focuses on the amount of work involved.
- Complexity focuses on the level of understanding and investigation needed.
- Uncertainty focuses on the unknowns and potential surprises that might arise.
- Risk focuses on the potential for problems and their impact on the project.