Miscelaneous

What are fragments in sequence diagram?

What are fragments in sequence diagram?

In sequence diagrams, combined fragments are logical groupings, represented by a rectangle, which contain the conditional structures that affect the flow of messages. A combined fragment contains interaction operands and is defined by the interaction operator.

What are lifelines in sequence diagram?

Lifelines. A lifeline represents an individual participant in a sequence diagram. A lifeline will usually have a rectangle containing its object name. If its name is “self”, that indicates that the lifeline represents the classifier which owns the sequence diagram.

What are the basic elements of a sequence diagram?

Basic Sequence Diagram Notations

  • Class Roles or Participants. Class roles describe the way an object will behave in context.
  • Activation or Execution Occurrence.
  • Messages.
  • Lifelines.
  • Synchronous Message.
  • Asynchronous Message.
  • Reply or Return Message.
  • Self Message.

What are the parts of a sequence diagram?

The following nodes and edges are typically drawn in a UML sequence diagram: lifeline, execution specification, message, combined fragment, interaction use, state invariant, continuation, destruction occurrence. Major elements of the sequence diagram are shown on the picture below.

Why do we use sequence diagrams?

The sequence diagram is a good diagram to use to document a system’s requirements and to flush out a system’s design. The reason the sequence diagram is so useful is because it shows the interaction logic between the objects in the system in the time order that the interactions take place.

What are the major elements of an UML sequence diagram?

The following nodes and edges are typically drawn in a UML sequence diagram : lifeline, execution specification, message, combined fragment, interaction use, state invariant, continuation, destruction occurrence. Major elements of the sequence diagram are shown on the picture below. Major elements of UML sequence diagram.

What does assertion fragment in UML 2 mean?

Assertion fragment (denoted “assert”) designates that any sequence not shown as an operand of the assertion is invalid. Loop fragment encloses a series of messages which are repeated. The following diagram shows a loop fragment. There is also an interaction occurrence, which is similar to a combined fragment.

How are interaction fragments used in sequence diagrams?

Interaction use is an interaction fragment which allows to use (or call) another interaction. Large and complex sequence diagrams could be simplified with interaction uses. It is also common to reuse some interaction between several other interactions. Referenced interaction has formal gates.

What is an interaction occurrence in UML 2?

An interaction occurrence is a reference to another diagram which has the word “ref” in the top left corner of the frame, and has the name of the referenced diagram shown in the middle of the frame. A gate is a connection point for connecting a message inside a fragment with a message outside a fragment.