Please note that the product backlog board has been superseded by the Product Canvas, a new type of backlog designed for creating new products and for product updates aimed at new markets. It extends the backlog board and connects personas with the product features. Please see my post “The Product Canvas” for more information.
A Multidimensional, Nonlinear Product Backlog
Most product backlogs I have come across either contain too much or too little information, ranging from literally a handful of user stories to many hundred items. Many backlogs don’t consider non-functional requirements and do not provide high priority items that are “ready” – clear, testable and feasible.
How come product owners and teams struggle to use the product backlog effectively? One of the reasons lies in the linear nature of a traditional product backlog: It is a list of “features, functions, technologies, enhancements, and bug fixes,” as Schwaber and Beedle (2002) write. Such a list can work well for updating an existing product. But it is often insufficient for developing a new product. I have therefore started to work with a multidimensional and nonlinear product backlog, which I call “Product Backlog Board.” Here is a sample product backlog board:
The product backlog board depicted above provides the following elements:
- A prioritised story area with a ready section and a section containing themes with their epics.
- A constraint area with the global operational qualities and the critical product design and user interface requirements.
- An optional model area that contains requirement models.
I am not the first person to recognise that flat product backlogs can be inappropriate; Jeff Patton did so a few years ago when he developed his story maps, for instance. You could even use a story map within your product backlog board if you wanted.
The Story Area
The story area is divided into two sections: items that are likely to be worked on in the next sprint, and the other outstanding work that is essential to create a successful product. The items in the ready section must be clear, feasible and testable. They are preferably captured as small and detailed user stories with well-written acceptance criteria. The epics, however, are coarse-grained and sketchy. They are placeholders for future detailed stories which are progressively derived from them. Epics are grouped into themes with each theme representing a product capability.
The stories in the ready section must be strictly prioritised, from one to n, to focus the work of the team. You don’t have to order the themes and epics unless you want to indicate when functionality will be released, for instance, in form of an early product increment (beta). But don’t forget to review the epics on a regular basis, and consider risk and uncertainty as well as dependencies. This will help you to decide how to stock the ready section and to determine which stories have to be carved out of your epics.
The Constraint Area
This area contains the global non-functional requirements of the product – operational qualities as well as product design and user interface ideas that apply to the entire product. It’s important to recognise and address these constraints: They influence the user experience, drive architecture and the technology decisions, impact the total cost of ownership and the product’s life expectancy. I prefer to capture operational qualities using constraint cards. The critical aspects of product and user interface design are best described visually as sketches or screenshots of mockups and prototypes. Note that the items in the constraint area are not estimated. Instead, the definition of done states that all constraints must be fulfilled. (I discuss design in more detail in my post on Agile User Interface Design.)
The Model Area
Workflows and models don’t fit into a linear, flat product backlog. Consequently, many Scrum teams ignore them. While requirements modelling should be applied lightly in an agile context, teams often benefit from connecting individual stories and epics, for instance, by showing how the user roles interact with the epics. The same is true for workflows: It’s often helpful to look at a user story sequence to understand how a user interacts with the product and to explore the resulting user experience. If requirement models and workflows are helpful to develop your product, then add a model area to the product backlog board. Like the constraint items, the models and workflows are not estimated. But they are also not included in the definition of done, as they simply elaborate stories and epics. (I describe user story sequences and workflows in more detail in my post on user story modelling.)
Making the Information Visible and Accessible
The product backlog should be visible and easily accessible for everyone involved in the development effort. I hence prefer to work with a physical product backlog board – paper cards and paper sheets put up on a large board or an office wall. On distributed projects, you can easily store the product backlog board as an electronic spreadsheet. Just remember to make it visible, for instance, by posting it on the project wiki.
Stocking the Product Backlog Board
I prefer to derive the contents of the product backlog board from the product roadmap and to focus its content on the items that are essential to develop the next product version or the next major release. This reduces complexity, creates clarity, and avoids predicting an uncertain future.
When you stock the constraint area, resist the temptation to create the complete product and user interface design upfront. Rather focus on those aspects that significantly influence the success of the product and that are difficult to change at a later stage. The detailed design should evolve from sprint to sprint based on customer and user feedback.