Final answer:
The event decomposition technique is used to identify use cases by breaking down a system into components based on external, temporal, and state events.
Step-by-step explanation:
The technique used to identify use cases based on external, temporal, and state events is the event decomposition technique. This approach involves breaking down the system into smaller, more manageable components based on different types of events that can happen in the system.
External events are triggered by actors outside the system, temporal events occur as a result of time passing, and state events are a result of a change within the system itself. By analyzing these events, it's easier to pinpoint functionality and define clear use cases for the design of the system.
Decomposing complex systems into smaller elements also aligns with methods where engineers might search externally for ideas to solve subproblems identified, leveraging information from various sources including customer interviews or technical databases.