A bounded context is an explicit boundary within which a domain model and its ubiquitous language have consistent meanings. It turns shared understanding of a complex domain into a model with clear limits, while allowing the model to evolve toward deeper insight. section 2.2.1
Find useful boundaries by iterating through the domain with practical heuristics:
- Split according to language, departments, or actors. section 3.3.1
- Begin with intuitive boundaries, then refine them as experience, heuristics, and understanding grow. section 3.3.1
- Align boundaries around parts of the domain requiring different expertise and knowledge. section 9.5
- Keep business logic that changes together inside the same boundary, and deploy what changes together. section 3.3.3
BigScreen's first boundaries
An EventStorm about purchasing cinema tickets provides input for design activities. Applying the natural-boundaries heuristics produces Movie Scheduling and Ticket Purchasing. Further iterations add Payments, reconsider Ticket Purchasing as Ticketing, and identify possible Price Calculation and Seat Allocations contexts.
A bounded context is not the same as a deployable unit. Several contexts may share one deployable unit, while one context may have multiple deployable units, although splitting one context increases the chance that dependent logic changes together. section 3.3.3
