Rules

• Name: The value can be anything.

  The name of the diagram.

• Documentation: The value can be anything.

  A textual description of the element.

An element of one of the following kinds:

• Activity (Activity)

  An activity is the specification of parameterized behavior as the coordinated sequencing of subordinate units whose individual elements are actions.

• Class (Class)

  A class describes a set of objects that share the same specifications of features, constraints, and semantics.

  A class may be designated as active (i.e., each of its instances having its own thread of control) or passive (i.e., each of its instances executing within the context of some other object).

  A class may also specify which signals the instances of this class handle. A class has the capability to have an internal structure and ports. Class has derived association that indicates how it may be extended through one or more stereotypes. Stereotype is the only kind of metaclass that cannot be extended by stereotypes.

• Component (Component)

  A component represents a modular part of a system that encapsulates its contents and whose manifestation is replaceable within its environment.

  In the namespace of a component, all model elements that are involved in or related to its definition are either owned or imported explicitly. This may include, for example, use cases and dependencies (e.g. mappings), packages, components, and artifacts.

• Device (Device)

  A device is a physical computational resource with processing capability upon which artifacts may be deployed for execution.

  Devices may be complex (i.e., they may consist of other devices).

• Execution Environment (Execution Environment)

  An execution environment is a node that offers an execution environment for specific types of components that are deployed on it in the form of executable artifacts.

• Interaction (Interaction)

  An interaction is a unit of behavior that focuses on the observable exchange of information between connectable elements.

• Node (Node)

  A node is computational resource upon which artifacts may be deployed for execution. Nodes can be interconnected through communication paths to define network structures.

• Opaque Behavior (Opaque Behavior)

  An behavior with implementation-specific semantics.

• Protocol State Machine (Protocol State Machine)

  A protocol state machine is always defined in the context of a classifier. It specifies which operations of the classifier can be called in which state and under which condition, thus specifying the allowed call sequences on the classifier's operations.

  A protocol state machine presents the possible and permitted transitions on the instances of its context classifier, together with the operations which carry the transitions. In this manner, an instance lifecycle can be created for a classifier, by specifying the order in which the operations can be activated and the states through which an instance progresses during its existence.

• State Machine (State Machine)

  State machines can be used to express the behavior of part of a system.

  Behavior is modeled as a traversal of a graph of state nodes interconnected by one or more joined transition arcs that are triggered by the dispatching of series of (event) occurrences. During this traversal, the state machine executes a series of activities associated with various elements of the state machine.

• Stereotype (Stereotype)

  A stereotype defines how an existing metaclass may be extended, and enables the use of platform or domain specific terminology or notation in place of, or in addition to, the ones used for the extended metaclass.