As an Agile practitioner, you likely utilize techniques like user stories and timeboxed Sprints to deliver value quickly. But when a user story is too complex to estimate, you may need to dig deeper before bringing it into a Sprint. This is where spike stories come in.
Spike stories enable Agile teams to thoroughly investigate and break down unclear user stories to build accurate estimates. Though often misunderstood, they provide immense value by helping you understand complex stories, reduce waste, and improve team efficiency when planning Sprints.
In this post, we will explore the purpose of spike stories in Agile and how to leverage them for maximized team performance.
What is a Spike Story in Agile?
A spike story is a special type of user story utilized in Agile frameworks like Scrum or Kanban. While traditional user stories describe functional features or requirements for your product, a spike story is used when the team needs to do investigative work to size or estimate another user story.
Spike stories allow your team to delve into the unknowns and complexities of a particular story so you can better analyze the required efforts. You typically timebox spike stories to focus the investigation during a short period, like an iteration.
The goal is to gain just enough understanding to estimate the original story’s scope accurately. While you do not intend to deliver product functionality from spike stories, they provide the vital upfront research to break down large stories into well-defined, actionable pieces.
Purpose of Agile Spike Stories
Spike stories serve several integral purposes in Agile frameworks. By incorporating spike stories into your Sprints, you can:
1. Estimate Complex Stories
Spike stories allow you to investigate large or complex user stories that your team cannot immediately estimate.
Through focused spikes, you can break these stories down into smaller, measurable units to build more accurate estimates. This prevents teams from prematurely guessing on effort and resources.
2. Reduce Waste
Good spikes help minimize wasted effort by ensuring your team does not dive into overly broad stories without enough details.
Timeboxing spikes also prevents wasted time from endless research. You get just enough information to estimate and move forward.
3. Understand Scope
Spikes enable your team to properly scope ambiguous stories before bringing them into a Sprint.
Rather than making assumptions, spikes let you answer questions to clarify the scope. This allows you to avoid unexpected scope creep down the line.
4. Gain Knowledge
The investigative nature of spikes provides opportunities for your team to gain valuable domain knowledge and technical insights which allow you to explore uncertainties before committing to large efforts.
How to Write a Spike Story
Writing solid spike stories takes practice, but will help your team get valuable information to build well-groomed Product Backlogs.
When constructing spike stories, follow these guidelines to ensure they are scoped properly:
1. Define a Clear Objective
Spike stories should have a narrowly defined goal to bind the investigation. Ask specific questions like “What API calls are needed to get this data?” rather than broad ones like “How do we build this feature?”.
2. Timebox the Work
Agree on a fixed time limit for the spike with your team, usually 1-3 days. This prevents never-ending rabbit holes. Timeboxing forces your team to focus on only the most essential information needed.
3. Plan Spike Execution
Determine who will work on the spike and what resources they need before bringing it into a Sprint. Spikes do not necessarily need a full Agile team. Often, 1-2 people like architects or lead engineers can investigate.
4. Avoid Prescriptive Solutions
Spikes should explore potential options, not prescribe solutions. The goal is to gather just enough data to size the original story, not finalized designs. Spikes often prototype options through proof-of-concepts or experiments.
5. Document Findings
Have the members working on the spike share results with the broader team, especially insights that can shape the real user story’s requirements. Treat spikes like any other Product Backlog item and add notes in your tracking system.
6. Estimate the Original Story
With results from the spike, the team can estimate the original story’s scope and resources needed. Use this estimate to prioritize the story in your Product Backlog accordingly.
What is the Difference Between a Story and a Spike in Agile?
In Agile, stories and spikes serve distinct purposes. A user story represents a small, deliverable piece of functionality that adds value to the end-user. You’ll typically write stories from the user’s perspective, following the format: “As a [user], I want [feature] so that [benefit].”
Spikes, on the other hand, are time-boxed research tasks. They help teams explore uncertainties or technical challenges that might impede story estimation or implementation. Unlike stories, spikes don’t directly produce user-facing features. Instead, they generate knowledge or prototypes that inform future work.
When you encounter a story that’s difficult to estimate due to technical unknowns, consider creating a spike. This allows your team to investigate potential solutions without committing to full implementation. Once completed, a spike’s findings enable more accurate estimation and planning of related stories.
Remember, while stories are part of your Product Backlog, spikes are temporary explorations that support the overall development process.
Spike Story Example
Let’s walk through an example of an Agile spike story to reinforce the core concepts:
The Product Owner adds a user story to integrate a facial recognition API into the mobile app for easier user login. However, the dev team is unfamiliar with the technical challenges and effort required to integrate this new API.
To investigate, the team creates a spike story to research the API, run integration proofs-of-concept, and document any blocking issues discovered. They timebox the spike to 3 days to determine whether integrating this API is feasible within a single Sprint.
Two engineers work on the spike. They successfully call the API using sample data and build a basic integration demo. However, they uncover that the API’s monthly allotment of free searches is capped. The engineers document this limitation for the Product Owner to consider.
With these spike findings, the development team now understands the integration approach and has identified a potential cost blocker. They estimate that the main story will require 5 days of effort accounting for the API search limits. This story estimate provides valuable data to the Product Owner on viability and priority.
Final Thoughts on Spike Stories in Agile
In summary, spike stories are a brief but powerful technique that allow Agile teams to investigate, estimate, and break down complex user stories before bringing them into a Sprint.
By taking the time to perform spikes on unclear stories, you can understand the scope, reduce waste, and improve team efficiency in your iterations. Though often misunderstood, leveraging spike stories in your process will enable your team to deliver more value by promoting informed planning and decision-making.
Keep spike stories in your Agile toolkit to help maximize your team’s performance.
