Many tools can store and maintain a hierarchy of data. A simple database can be constructed to do what you need quickly and inexpensively. However, there are a number of features to look for when choosing or even designing a tool for this purpose:
- Graphical display - It’s best to display the hierarchy on a projector during a story gathering workshop. This shows the big picture of the product backlog and where new stories are being added in the hierarchy.
- Dynamic editing and display of branches - Sometimes entire branches of the tree will be moved or deleted during the workshops. It’s best if this can be done by right-clicking or dragging the branch you wish to change. Sometimes the group will want to focus on a single branch in detail. It’s very useful to be able to collapse all the other branches and just display the branch the group wants to discuss.
- Graphical options for individual stories - Stories may be prioritized, flagged for attention or have additional information attached to them during the meeting. A tool that is extensible and allows meta-data attached is beneficial.
- Flexible - The tool must not impose too much structure. It should allow the creation of sections such as a “parking lot” for future story ideas, etc.
- Powerful export capabilities - The tool should be able to export data to a variety of popular and readable formats for sharing with customers who do not wish to buy or learn the tool. Export formats like Word or Excel are a must.
I have used mind map tools such as MindManager and FreeMind for building and tracking product backlogs in the past and can recommend them.