Model Parts, Diagrams, Dictionary Items, and Properties > Dictionary items > Constraint (dictionary item)
  
Constraint (dictionary item)
For automation interface information about a Constraint, click here Constraint (automation interface).
A constraint is a limitation imposed upon the functionality of a system. It has measurable and testable values.
You can create a Constraint in the following ways:
• Through the context menu of most items types. When you create a Constraint from the context menu of an item, Modeler applies the Constraint to the owning item (except when the owning item is the Model or a Package)
• Through the Items tab of an item's Property Pages.
• Through most diagram types. When you create a Constraint on a diagram, the Constraint is owned by the item that owns the diagram. On a diagram, you can apply a Constraint to an item by creating a Link Note between the Constraint and the item.
Note that if a Constraint is not applied to any items and you use a Link Note to apply that Constraint to an item, Modeler rescopes the Constraint to that item. If a Constraint is applied to one item and you reconnect its Link Note on a diagram, Modeler rescopes the Constraint to the applied item.
Specify the text of a Constraint through its Full Text property, which appears on the Full Text tab of its Property Pages.
You can view which items a Constraint applies to in the following ways:
• On a Constraint's Property Pages, you can see which items the Constraint is applied to through the Items tab – in the Show Associated list, select Constrainees, and then the items to which the Constraint applies are listed
• A Usage report for a Constraint reports which diagrams the Constraint appears on and which items the Constraint is applied to.
• In the Relationships pane, you can expand a Constraint, and then expand the Constrainees folder.
When used on a Constraints Diagram, a Constraint's notation is as follows:
For information about the View Options available for this symbol, see Constraint view options - constraint diagram.
When used on any diagram other than a Constraints Diagram, a Constraint's notation is as follows. By default, the value of the Full Text property is shown on the diagram:
In the Modeler panes, a short-cut symbol on the Constraint's icon indicates that the item is a stub.
On a Class Diagram, you can show the Constraints that are applied to Class' Attributes and Operations through the View Options of the Class – select the Show Constraints check box.
The following sections provide information about how a Constraint is used in the model. For more information about a property, item, model part or diagram, click it.
Properties
In addition to the standard properties, a Constraint has these properties:
• Best Possible
• Constraints
• Current Level
• Full Text (Real RTF through the Automation Interface)
• Measure
• Measuring Instrument
• Target Level
• Visibility
• Worst Acceptable
Owned by
Accept Event Action
Activity
Activity Final Node
Activity Partition
Actor
Actual Template Parameter
Add Structural Feature Value Action
Alternative Choice
Association
Atomic State
Attribute
Basic Type
Board
Board IO Device
Board IO Device Type
Board Type
Call Behavior Action
Call Operational Action
Central Buffer
Channel
Class
Clear Association Action
Clear Structural Feature Action
Column
Concurrent State
Connection Point Reference
Control Flow
Create Link Action
Create Object Action
Data Store
Data Type
Database
Decision Node
Dependency
Destroy Link Action
Destroy Object Action
Disk
Disk Type
Entry State
Enumeration Literal
Event
Event Action Block
Event Flag
Exception
Exception Handler
Exit State
Final State
Flow Final Node
Formal Template Parameter
Fork Node
Fork State
Generalization
History State
Increment
Index
Initial Node
Initial State
Input Pin
Instance
Interface
Interface Device
Interface Device Type
Interruptible Activity Region
IO Flow
Join Node
Join State
Junction State
Mailbox
Memory
Memory Type
Merge Node
Model
Monitor
Multidrop Bus
Multidrop Bus Type
Object Flow
Opaque Action
Output Pin
Operation
Package
Parameter
Point to Point Connection Type
Pool
Processor
Processor Type
Qualifier
Read Extent Action
Read Link Action
Read Self Action
Read Structural Feature Action
Reception
Relationship
Remove Structural Feature Value Action
Role
Semaphore
Sequential State
Send Signal Action
Signal
State Machine
Stereotype
Structured Activity Node
Submachine State
Subsystem
Synchronizer
Table
Task
Ternary Association
Ternary Role
Test Identity Action
Transition
Type Definition
Use Case
Value Specification Action
Variant
Variation Point
Owns
Comment
Dependency —The Dependency is owned jointly by the Constraint and the other associated item. The access permissions you have to a Dependency are determined by the access permissions of the dependent item.
Defined in these parts of the model
Constraints Model
Used in:
Use Case Model
Shown on these diagrams
Activity Diagram
Class Diagram
Communication Diagram
Composite Structure Diagram
Concurrency Diagram
Constraints Diagram
General Flow Diagram
General Graphics Diagram
Object Diagram
Sequence Diagram
State diagram
System Architecture Diagram
Table Relationships Diagram
Use Case Diagram
Variant Diagram
For information about how the View Options affect the presentation of Constraints on a Constraints Diagram, see Constraint view options - constraint diagram
Can be linked to these dictionary items
In addition to the owning item, and the item the Constraint is applied to, a Constraint can be linked to the following items.
Constraint Type —The linked Constraint Type organizes the Constraint into a logical group. Note that the Options tab of a Constraint's Property Pages displays the linked Constraint Type.
Stereotype
Timing Constraint —The Constraint applies to the linked Timing Constraint. Note that if you link a Timing Constraint to a Constraint and then delete the Constraint, the linked Timing Constrain will also be deleted.
* 
Like most other items in a Model, a Constraint can be linked to an Activity Partition, Comment, Frame Box, General Node, General Flow, General Flow Diagram Node, General Flow Diagram Flow or Swimlane.