Artifact: System Context Diagram
Represents the System, Actors with which it interacts, and information they exchange and the direction of information flow.
Domains: Systems Architecture
Purpose
  • To better understand the interactions between the system under development with the external entities (represented as actors).
  • To understand the services required of the system.
  • To delineate the boundaries of the system.
  • To ensure that the appropriate requirements are present and being developed.
Relationships
Description
Main Description

The system context diagram describes the top-level collaboration showing the system (modeled as a top-level subsystem), its interfaces and its relationships with its actors, including the external I/O entities that flow between actor and system.

Main information captured in the system context diagram:

  • The interfaces to be realized by the system (in terms of the operations the systems provides, and the associated protocols supported, the state variables and stores that the system realizes, and attributes).
  • The I/O entities that flow between the system and its actors.
  • The interfaces required by the system (to be realized by the actors which interact with the system) for correct performance. Often, if the actor represents an existing system with which the system must communicate, these required interfaces simply reflect constraints imposed by that other system.
Tailoring
Impact of not havingWithout this artifact, understanding the boundaries of the system under development and how it interacts with the external environment would be very difficult.
Representation OptionsBlock Definition Diagram with I/O Entities and direction stereotypes.