Why Developers Use Story Points and Testers Focus on Time?
The question “Why Developers Use Story Points and Testers Focus on Time” is a question I just received from from one of my students.
I would say that this question highlights a common point of confusion in Agile teams. While developers often focus on story points to estimate the complexity, effort, or risk of completing a user story, testers may find themselves needing to focus on time-based estimations for specific reasons tied to their role.
Let’s break this down and explain why both approaches are valid but serve different purposes.
Why Developers Use Story Points?
Developers use story points because they provide a relative measure of effort that isn’t tied to specific hours or days. Story points account for:
- Complexity: How challenging is the task?
- Effort: How much work is required?
- Uncertainty/Risk: Are there unknowns that might impact delivery?
Story points allow developers to abstract away from rigid time constraints and instead focus on comparing tasks relative to one another.
Example: A 5-point story is generally considered twice as complex as a 2-point story.
This works well for development work that involves creative problem-solving and unforeseen challenges.
But…
Why Testers May Need to Focus on Time?
As a software tester specialist, your role often requires a more granular understanding of how long testing activities will take because:
- Testing Tasks Are Sequential (and I am not referring to the Waterfall model): Unlike development, where multiple tasks can sometimes run in parallel, testing often follows a sequential process (e.g., test case creation, execution, defect retesting). Knowing how many hours you’ll need helps ensure that testing fits within the sprint timeline.
- Defect Resolution Timing: Testing depends heavily on when developers complete their work. If a developer finishes a feature late in the sprint, you’ll need to allocate remaining hours efficiently to test it thoroughly. Time-based estimates help you plan for these dependencies.
- Automation Script Development: Writing automation scripts or executing non-functional tests often involves measurable, repeatable tasks. Estimating these in hours allows for better resource allocation and scheduling with Continuous Integration (CI) pipelines.
- Stakeholder Communication: Stakeholders (like Product Owners) often want to know when something will be tested and released. Providing time-based estimates gives them clarity about timelines and helps manage expectations.
Example: If a user story historically took 16 hours to test across multiple sprints, using this historical data ensures that your sprint commitments remain realistic. This level-specific detail is harder to capture with story points alone.
Bridging the Gap Between Story Points and Hours
So, what do you think, about how to bridge this gap?
The key is not to see story points and time-based estimates as competing approaches but as complementary tools. Here is what I think can bridge the gap:
- Collaboration: Work closely with developers to understand the scope of each story point. For instance, ask questions like, “What aspects of this 5-point story will require additional testing?” This helps you align your time estimates with the team’s overall effort estimation.
- Use Historical Data: Just as developers refine their story point estimates over time, testers can use historical data to correlate story points with actual testing hours. Example: If a 5-point story consistently takes 16 hours to test, this becomes a benchmark for future sprints.
How to Think About It as a Tester?
As a tester, your mindset should balance the flexibility of story points with the precision of time-based estimates. I always ask myself:
- What are the critical testing tasks for this sprint, and how much time will they realistically take?
- How do my time estimates align with the team’s overall story point commitments?
- Am I accounting for potential delays, such as waiting for defect fixes or coordinating with other team members?
This way you too can contribute to a shared understanding of what’s achievable within the sprint.
So, Why Developers Use Story Points and Testers Focus on Time?
To summarize, developers focus on story points to gauge complexity and effort, while testers often focus on time to ensure testing activities fit within the sprint.
But this is not the rule set in stone. You can change it later if needed.
Both approaches are valuable, and the key is to integrate them effectively during sprint planning. I really believe that if you use historical data correctly and collaborate closely with the team will help you strike the right balance.
Your Next Step
After your next sprint, document how long specific testing activities took and compare them to the story points assigned to those user stories. Over time, this will help you build a reliable framework for estimating testing efforts in future sprints.
