The Difference Between a Sequence & Collaboration Diagram

Sequence and collaboration diagrams are forms of interaction diagrams used in the modeling of the relationship between a computer program and its users. These models describe the manner that code and data interact in the completion of a particular task. Each performs this modeling in a distinct manner.

Object Behavior Vs. Relationship

In sequence diagram models, the descriptions of the data and codes illustrate the expected actions of behavior. For collaboration diagrams, the descriptions are used to illustrate the relationships of these sequences to one another.

Type Vs. Order of Message

The modeled behavior shown in a sequence diagram is used to show the messages passed between the codes and data. Collaboration diagrams vary in that they illustrate the order of the command message rather than the messages.

Basic Construction

Sequence diagrams tend to be much more complex than collaborative diagrams. Read in a left to right and then descending manner, the data and code classes are generally not shown. In addition, conditional messages inform of certain fluctuations in the conditions related to the object. In collaboration diagrams, data and codes are shown as icons with arrows illustrating where messages are being passed. Messages are designated with numbers that generally follow a one, two, three format.

References

• Object-Oriented Design and Analysis Team - Kennesaw University: "Unified Modeling Language Tutorial - Interactive Diagrams": Tom Gooch
• Search Software Quality Definitions: "Use Case"
• Software Design: "What is Object-Oriented Software"