If needed, an object can also represent more than one class.Ī package symbol is used to contain interactive elements of the diagram. Decisions are used to reflect the previous activity.ĭepicted with a rectangle shape, objects represent an instance of a class. The activity is depicted with a diamond shape in the diagram. These are used to show where a decision will be taken in the system.

This is shown in the diagram with the use of an arrow pointing towards the direction. The Control flow is used to show the order in which statements, function calls and instructions of the program are executed. Just like the Initial State, there is a notation for the final state too, which shows the final state of the workflow in the diagram.

The initial state is shown by a circle, and as you can guess, we use it to denote the initial state of the workflow. These are used to show the start or end of concurrent activities in the diagram. Simply put, Object flow shows the path along which the data passes. We also use it to describe state changes that trigger by events. The shape of a State is used to denote the condition of an event or activity in the system. In Unified Modelling Language, Activity is a shape that is used to show a major task that must be completed to fulfill an operation contract. These interactions and objects have some symbols and notations that are used to standardize UML Structure Diagrams.Īn actor is used in UML to specify a role that is either played by a user or any system that is going to interact with the objects of the system. On the top, you can see the beginning, and then the diagram flow descends downwards to mark the sequence of all interactions in the system. UML Sequence Diagrams are designed so that they can depict a timeline. Symbol and Components of a UML Sequence Diagram

Many Businessmen also use these diagrams to understand and establish systems too. Sequence Diagrams are used mostly by software developers to note down and understand the requirements of new and pre-existing systems.The diagram is used to depict the interaction between several objects in a system. As you can guess from its name, the Sequence diagram shows the order in which interactions take place.A Sequence Diagram is one such type of diagram that can be designed with UML.Some of these are Interaction Diagrams, Structure diagrams, and behavior diagrams. We can design diagrams using the Unified Modelling Language in many ways.

System sequence diagram online