If you've ever stared at a Product Backlog Item (PBI) that feels too big or too fuzzy and thought, "Where do I even start?", you're not alone.
In Scrum, your Product Backlog is like a living artifact, and if the items in it are too chunky, vague, or oversized, the team struggles to make progress. That's where **decomposition** comes in.
Let's break this down — simply and clearly.
What Does it Mean to "Decompose" a PBI?
Decomposition means breaking down a big Product Backlog Item into smaller, more manageable pieces that can be completed within a Sprint. It's like taking a large Lego structure and breaking it into smaller, buildable sections.
The goal?
Better clarity
Smarter planning
Faster feedback
More predictability
Two Common Techniques: Splitting vs. Slicing
Many people use these terms interchangeably, but they are not exactly the same. Here's how we explain it in our PSPBMS class:
SPLITTING — "Breaking into smaller parts"
- Think of splitting as dividing a large item into smaller chunks that still make sense on their own.
- It's like splitting a pizza into slices — each slice is complete and edible on its own.
- Ideal for big epics, user stories, or features.
Example:
Big PBI: "Create user profile functionality"
You can split it into:
- "Allow users to create a profile"
- "Allow users to upload a profile picture"
- "Enable users to edit profile information"
These are separate functionalities, but together they complete the feature.
SLICING — "Cutting vertically through value"
- Slicing focuses on delivering a thin slice of end-to-end value, even if it’s not feature-complete.
- It's like cutting a layered cake vertically — you get a bit of everything: frosting, filling, sponge — in one slice.
Example:
Same big PBI: "Create user profile functionality"
Instead of breaking it by tasks or modules, slice by user journey or use case:
- "Guest can create basic profile with name and email"
- "Registered user can create full profile with photo & bio"
- "Mobile user can create profile via app"
Each slice is usable, testable, and delivers value, even if it’s not the entire feature.
When to Use Which?
Use splitting when:
- The item is too big or complex to finish in one Sprint
- You can clearly separate the pieces of functionality
Use slicing when:
- You want fast feedback on real user value
- You're building incrementally and iteratively
- You're dealing with high uncertainty or innovation
In our AgileWoW PSPBMS workshop, you'll practice both techniques with real-world examples and AI assistance.