Actors that invoke a use case are what?

Actors that invoke a use case are what?

• A. Primary actors
• B. Secondary actors
• C. External actors
• D. Supporting actors

Answer: (A)

Primary actors are the people or roles that trigger a use case to achieve a goal with the system. They initiate the interaction that starts the sequence of events in the use case. For example, a customer places an order, which starts the “Place Order” use case—the customer is the primary actor because they actively initiate the process to get a result from the system. Secondary actors, by contrast, participate in the use case to help it run but don’t initiate it themselves—think of a payment processor or a clerk who supplies information. External actors describe who sits outside the system boundary, but this doesn’t indicate who starts the use case. Supporting actors is a less precise label for those who assist; the essential distinction is that the initiator is the primary actor.

Primary actors are the people or roles that trigger a use case to achieve a goal with the system. They initiate the interaction that starts the sequence of events in the use case. For example, a customer places an order, which starts the “Place Order” use case—the customer is the primary actor because they actively initiate the process to get a result from the system.

Secondary actors, by contrast, participate in the use case to help it run but don’t initiate it themselves—think of a payment processor or a clerk who supplies information. External actors describe who sits outside the system boundary, but this doesn’t indicate who starts the use case. Supporting actors is a less precise label for those who assist; the essential distinction is that the initiator is the primary actor.