Definition:
Disaggregation is a process of splitting a user story or feature into smaller, easier-to-estimate pieces, in order to ensure an effective delivery of a product and reduce the complexity. Smaller stories allow faster, more reliable implementation, since small things go through a system faster, reducing variability and managing risk. Splitting bigger stories into smaller ones is, thus, a mandatory survival skill for every Agile team. It’s both the art and the science of incremental development.
Agile teams use story points and ‘estimating poker’ to value their work [2, 3]. A story point is a singular number that represents a combination of qualities:
Agile teams often use ‘estimating poker,’ which combines expert opinion, analogy, and disaggregation to create quick but reliable estimates. Disaggregation refers to splitting a story or features into smaller, easier to estimate pieces.
Further Reading:
Lean from the Trenches: Managing large scale projects with Kanban by Henrick Kniberg