Here's a breakdown of what actors represent:
* External Entities: Actors are outside the system boundary. They initiate actions within the system, interact with it, and receive results.
* Types of Actors: Actors can be individuals (customers, employees), organizations (banks, suppliers), external systems (databases, other applications), or even physical devices (sensors, ATMs).
* Roles, not Individuals: An actor represents a role or a type of user, not necessarily a specific person. For example, "Customer" is an actor, representing anyone who interacts with the system as a customer.
* Communication with the System: Actors communicate with the system by initiating use cases, providing input, and receiving output.
* Visual Representation: In diagrams, actors are typically represented by stick figures.
Why are actors important?
* Understanding System Boundaries: Actors help define the system's scope and what it interacts with.
* Identifying Requirements: They help pinpoint the system's functionalities by illustrating the interactions users need to have.
* User Perspective: They provide a user-centric view of the system, emphasizing how it will be used.
Examples of Actors:
* Online Store: Customer, Administrator, Shipping Company
* Hospital System: Doctor, Nurse, Patient, Insurance Company
* ATM: Customer, Bank System
* Social Media Platform: User, Advertiser, Developer
By understanding actors and their roles, you can create more accurate and complete use case diagrams, which ultimately leads to a better understanding of the system's functionalities and how it will be used.