Creating sequence diagrams

In UML models, an interaction is a behavior that represents communication between one or more participants. A sequence diagram is a UML interaction diagram that models the messages that pass between participants, such as objects and roles, as well as the control and conditional structures, such as combined fragments. You can create new sequence diagrams, populate existing sequence diagrams with source elements, add lifelines, messages, and combined fragments to sequence diagrams.

About this task

IBM® DevOps Model Architect supports and promotes the adoption of several IBM practices, including the component-based software architecture practice.
Component-based Software Architecture Practice
The Component-based Software Architecture Practice defines a system's functional architecture by breaking the system up into a number of collaborating components. It focuses on identifying the major abstractions of the system and making decisions on how the system will be built to ensure resilience and maintainability.
  • Setting preferences for sequence and communication diagrams
    You can set several default preferences for sequence and communication diagrams. For example, you can specify the appearance of lifelines, messages, and execution occurrences that are displayed in sequence and communication diagrams when you create them.
  • Creating sequence diagrams from existing diagram elements
    You can create sequence diagrams in the typical way that you create any UML diagram, or you can create them from existing elements in your project. You can create a sequence diagram either within a model, which also creates a collaboration and interaction, or as a standalone diagram, which becomes a DNX file.
  • Creating sequence diagrams or communication diagrams from existing interactions
    When you are modeling the interactions between objects and if the model includes a sequence diagram, you can quickly create the corresponding communication diagram. Or, if the model includes a communication diagram, you can quickly create the corresponding sequence diagram.
  • Populating sequence diagrams
    You can create sequence diagrams and populate them with elements to understand and develop behaviors and interactions between objects in systems. You can add lifelines to represent objects or actors, messages to represent communication between the objects, and combined fragments to represent the control structures.
  • Organizing sequence diagrams
    You can organize sequence diagrams to better represent a system. You can reorder messages, delay asynchronous messages, as well as manage combined fragments and lifelines.
  • Deleting messages from sequence diagrams
    You can delete messages from your project that you no longer need. When you delete a message, you have different results depending on the type of message that you delete.
  • Deleting behavior execution specifications from UML diagrams
    When you create a synchronous or asynchronous message, a behavior specification is created automatically. You can delete a behavior specification from the model without deleting the message. You can also create an asynchronous message without a behavior specification by selecting Asynchronous Signal Message (No BES) from the Palette.
  • Deleting lifelines from UML diagrams
    You can delete lifelines from UML diagrams, such as sequence or communication diagrams, to remove an object from an interaction. When you delete a lifeline, all send and receive messages that originate from the deleted lifeline are also deleted. When you delete a lifeline from a sequence diagram, all interaction fragments that cover the lifeline are deleted, but the combined fragments and interaction uses that cover other lifelines are not.
  • Interaction operators in sequence diagrams
    In sequence diagrams, an interaction operator defines the semantics of a combined fragment and determines how to use the interaction operands in the combined fragment.
Related concepts:
Sequence diagrams
Interaction frames
Related reference:
Example of a sequence diagram
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