Most software development teams today use Agile to work faster and deliver high-quality products. Among the many Agile frameworks, Scrum is the widely implemented framework that follows an iterative approach to product development in short development cycles called sprints. But what items or tasks to cover in each sprint? This is where the backlog comes into action. Backlog is a key component in Scrum that provides a list of all the items/tasks the team has to work on. But there are two backlog terms used in Scrum, i.e., product backlog and sprint backlog. So, let's explore in detail what product backlog and sprint backlog are and then list the key differences between them.
The product backlog is a list of things the development team must work on to achieve the overall product goals. It is not just a to-do list but also breaks down the items/tasks into smaller manageable tasks to make it easy for the development team to tackle them. Some of the common items included in a product backlog are:
The product backlog is solely created and prioritized by the Product Owner. The Product Owner gathers all the ideas, observations, feedback, and other information and develops a prioritized product backlog that includes all those items/tasks that can bring value to the product and help achieve the targeted goals. The prioritization of the product backlog depends on multiple factors, such as product value, dependencies, complexity, market demand, finances, etc.
The product backlog is not static and can change depending on user feedback, hidden complications, and other scenarios. Usually, there is a product backlog refinement after every few sprints to evaluate the remaining product backlog items and add/remove items depending on the current situation. Overall, the product backlog is a single source of truth for all the product-related work the team is/will do during the whole development phase.
A sprint is a time-boxed development period (mostly 1-4 weeks) where a team works on a specific set of items from the product backlog with the target of completing a shippable product increment at the end of the sprint. So, a sprint backlog is a list of things the development team will work on in the current sprint.
The sprint backlog is created from the product backlog by taking out the top-priority items and breaking them into specific, actionable tasks that the development team will work on during the sprint. For example, a sprint backlog can include tasks like:
In short, the sprint backlog is a small to-do list that will be completed within the time-boxed duration of the sprint. Since the development team is the main body dealing with the sprint backlog, it decides what items to include in the sprint backlog. However, the team can consult the Product Owner and Scrum Master while deciding the sprint backlog items.
Here you might have a question: if the sprint backlog is extracted from the product backlog, then why not just pick the top-most items of the product backlog instead of creating a sprint backlog?
Although the top-most items in the product backlog represent the highest priority items necessary to achieve main goals, they sometimes depend on other low-priority items. In addition, those top items might require a lengthy sprint duration, which is not what the team targets currently. Therefore, it is not necessary that the top-notch items of the product backlog will be the sprint backlog.
The development team conducts a sprint planning meeting where it evaluates the product backlog items and picks those items the team can easily complete in the sprint duration. Moreover, the sprint backlog also helps team members and stakeholders have a clear glimpse on what are the targets and end goals of the sprint. That's why it is important to create a sprint backlog despite having a prioritized product backlog.
From the above overview of the product backlog and sprint backlog, it is clear that both present the to-do list. However, the main purpose of both backlogs is different. So, let's dive deep and discuss the key differences between the product backlog and sprint backlog:
The first and most prominent difference between the product backlog and sprint backlog is the nature of the tasks listed in them. The product backlog contains all the tasks related to the whole project, which requires multiple sprints to complete.
On the other hand, the sprint backlog just includes a list of a few tasks that are going to be completed within the duration of the current sprint.
The product backlog is not static and gets updated with new product-related updates, feature demands, feedback, and similar other attributes. There is a dedicated event called "Backlog Refinement" in which the Product Owner, Scrum Master, and the development team review the existing backlog items and refine the backlog accordingly.
However, the sprint backlog is static. It gets prepared during the sprint planning meeting and includes only those items that the team can successfully complete within the sprint. No new items are added to the sprint backlog during the sprint period. But if some items are unable to be completed within that period or get stuck due to some complications, they can be shifted to the next sprint.
The product backlog is created and prioritized by the Product Owner. Basically, the Product Owner first gathers all the product-related ideas, suggestions, and feedback. Afterward, he creates a prioritized list of product backlog items. He might even translate items into user stories to make it easy for the development team to estimate the efforts. So, the development team is not directly involved in creating the product backlog.
The development team's interaction with the product backlog begins when it estimates the efforts of the backlog during the backlog estimation meeting using estimation techniques like Async Poker, Planning Poker, T-Shirt Sizing, Affinity Mapping, Dot Voting, etc. After the estimation, the development team might collaborate with the Product Owner to re-prioritize the product backlog.
Talking about the sprint backlog, it is created and managed entirely by the development team. The development team members gather for a sprint planning meeting where they discuss what items from the product backlog they intend to cover in the next sprint and then they create the sprint backlog accordingly. During this stage, they can interact with the Product Owner for suggestions, but the main creator and manager of the sprint backlog is the development team.
The product backlog is an independent list with no dependencies on any other list. It presents all the product-related items to achieve the main product goals, and the list can be updated with any set of new items.
The sprint backlog is totally dependent on the product backlog list. It can only include the items present in the product backlog, whether they are top-priority items or a few low-priority items. In short, the sprint backlog cannot include anything outside the scope of the product backlog.
In the product backlog, the Product Owner might translate the items into user stories. A user story is the description of the backlog item from the user's perspective. For example, as a salesperson, I want to see a complete list of leads, so that I can arrange the follow-up activities accordingly. User stories help the development team better understand the backlog items and do more accurate estimates of efforts.
When it comes to the sprint backlog, the user stories are further broken down into individual tasks so that the team can get deeper into the requirements, better estimate the time, and achieve the targets effectively. In short, the sprint backlog is a further breakdown of the product backlog items into smaller tasks.
The backlog plays a key role in Scrum-based development. The product backlog provides a complete list of items the development team has to complete for the product's success, while the sprint backlog provides a complete list of items the development team has to complete in the current shippable product increment. To sum up the discussion, we can conclude by saying that product backlog and sprint backlog both have a unique role in Scrum and their right use can lead to quality products.
