Cradle Stereotype Definitions

The following table provides definitions of the Cradle provided stereotypes. SysML stereotype elements are implemented using the Cradle Specification item type. A base set of stereotypes are supplied with Cradle 7.1 and later installations allowing all the basic elements of the nine SysML diagram types to be represented. A description of the base set of stereotypes can be found in Table 1 presented below. The range of stereotypes can be user enhanced in the Project Schema, allowing wider industry or language dependent terminology to be utilized, for example, «hardware» and «software» or «mechanical» and «electrical» could be defined as subtypes/descendants of the «block» stereotype.

Cradle Stereotype Definitions

Stereotype Name

Diagram Type

Diagram Subject Element





An accept change action responds to a conditional event such as change in a valueType or resource block.




An accept signal action responds to the receipt of a signal.




Actions execute and transform their inputs into outputs.




The input/output parameters of an activity can be grouped together into parameter sets.




An activity parameter models the flow of

matter, energy, or data into and out of an activity diagram.


act, bdd, sd, stm



An activity specifies the transformation of inputs to outputs through a controlled sequence of action executions.


bdd, ibd, sd


An actor represents the role of a human, an organization, or any external system that interacts with the system being developed.


act, bdd, Ibd, par, sd, stm, uc


bdd, ibd, uc, par

A block is a unit of structure used to define a type of thing (e.g., system or item that flows through the system).




A call behavior action can invoke / call another behavior diagram (act, stm, sd) for execution.




A call operation action can invoke / call an operation (i.e., activity) owned by a specific block.




A central buffer provides storage for multiple data objects of the same type before the objects are consumed by downstream actions.


bdd, par

bdd, par

A constraint is used to define performance constraints on the value properties of blocks and activities.




Control flow edges establish the order in which the actions within an activity will execute.




This action invokes / calls a controlOperator activity diagram to define control parameters for enabling and disabling other actions.




A controlOperator is associated with an activity diagram to define control parameters for enabling and disabling other actions.




A dataStore provides storage for a data object before the object is consumed by a downstream action.




An entryPoint can be used to define different entry points into another state machine.




An enumeration defins a set of named values called literials associated with a valueType.




An exitPoint can be used to define different exit points out of another state machine.




An Interaction/ sequence diagram can model a group of event occurrences using a special construct called a combined fragment.


bdd, ibd


A fullPort assigned to a block has a port definition block that defines valid incoming and/or outgoing items.




A pseudostate points to the last active state when a composite state was last exited.




An interaction is a unit of behavior that focuses on the observable exchange of messages between blocks and/or actors using sequence diagram.




An interfaceBlock is a kind of entity that defines a set of public features (i.e., operations and flow properties) a port must support.




An interrupting edge interrupts the execution of the actions in an interruptible region of activity diagram.




A libraryModel package that contains model elements that are intended to be reused by other packages.




A lifeline represents an individual participant (block or actor) in an Interaction / Sequence diagram.




A Message defines a particular communication between Lifelines of an Interaction/Sequence Diagram.




A model package is a special type of package that groups regular packages into a hierarchy of packages.




An object flow is an activity edge that can have objects or data passing along it.




An object node is an entity that flows through an activity.



bdd, pkg, uc, req

A package is a container/namespace for model elements, diagrams, and nested packages.




A pin is an object node for inputs and outputs to actions on activity diagram.


bdd, ibd


A proxyPort assigned to a block has a port definition interfaceBlock that defines valid incoming and/or outgoing items.


act, stm


The sendSignal action passes a signal to a receiver entity.


act, bdd, ibd, sd, stm


A signal defines an asynchronous message that can be sent and received by a block.




A stateMachine specifies the sequences of states that a block goes through during its life in response to events, together with its responses and actions.


act, sd, stm


A state represents some significant condition in life of a block.




A state machine may be reused using a kind of state called submachine state that invokes the reused state machine.




A transition specifies when a change of state occurs within a state machine.




A use case describes how users use the system to achieve their goals.


act, bdd, ibd, par, sd, stm


A valueType is a form of data value (e.g. integer, real, boolean, string) with a specified unit of measurement, a defined kind of quantity, and a value.




A viewpoint is used to specify conventions and rules for constructing and using a view for the purpose of addressing a set of stakeholder concerns.




A view is a special type of package that lists the model elements that support a particular stakeholder perspective.




A waitTime action corresponds to an expiration of an implicit timer in an activity diagram.