UML State machine diagram and activity diagram are both behavioral diagrams but have different emphases.
Next Page The name of the diagram itself clarifies the purpose of the diagram and other details. It describes different states of a component in a system.
A Statechart diagram describes a state machine. State machine can be defined as a machine which defines different states of an object and these states are controlled by external or internal events. Activity diagram explained in the next chapter, is State and activity diagrams in uml special kind of a Statechart diagram.
As Statechart diagram defines the states, it is used to model the lifetime of an object. Purpose of Statechart Diagrams Statechart diagram is one of the five UML diagrams used to model the dynamic nature of a system.
They define different states of an object during its lifetime and these states are changed by events. Statechart diagrams are useful to model the reactive systems. Reactive systems can be defined as a system that responds to external or internal events.
Statechart diagram describes the flow of control from one state to another state. States are defined as a condition in which an object exists and it changes when some event is triggered.
The most important purpose of Statechart diagram is to model lifetime of an object from creation to termination. Statechart diagrams are also used for forward and reverse engineering of a system. However, the main purpose is to model the reactive system. To model the life time of a reactive system.
To describe different states of an object during its life time. Define a state machine to model the states of an object.
How to Draw a Statechart Diagram? Statechart diagram is used to describe the states of different objects in its life cycle. Emphasis is placed on the state changes upon some internal or external events. These states of objects are important to analyze and implement them accurately.
Statechart diagrams are very important for describing the states. States can be identified as the condition of objects when a particular event occurs. Following is an example of a Statechart diagram where the state of Order object is analyzed The first state is an idle state from where the process starts.
The next states are arrived for events like send request, confirm request, and dispatch order. These events are responsible for the state changes of order object. During the life cycle of an object here order object it goes through the following states and there may be some abnormal exits.
This abnormal exit may occur due to some problem in the system. When the entire life cycle is complete, it is considered as a complete transaction as shown in the following figure.
The initial and final state of an object is also shown in the following figure. Where to Use Statechart Diagrams? From the above discussion, we can define the practical applications of a Statechart diagram.
Statechart diagrams are used to model the dynamic aspect of a system like other four diagrams discussed in this tutorial. However, it has some distinguishing characteristics for modeling the dynamic nature.
Statechart diagram defines the states of a component and these state changes are dynamic in nature. Its specific purpose is to define the state changes triggered by events. Events are internal or external factors influencing the system.
Statechart diagrams are used to model the states and also the events operating on the system. When implementing a system, it is very important to clarify different states of an object during its life time and Statechart diagrams are used for this purpose. When these states and events are identified, they are used to model it and these models are used during the implementation of the system.The state diagram from Figure 2 is an example of an extended state machine, in which the complete condition of the system (called the extended state) is the combination of a qualitative aspect—the state variable—and the quantitative aspects—the extended state variables.
Oct 22, · A UML activity diagram is a special case of a state chart diagram in which all of the states are action states and the transitions are triggered by the completion of actions in the source state.
Use an activity diagram to describe the internal behavior of a method and represent a flow driven by internally generated actions.
Activity diagram is used to document the logic of a single operation/method, a single use case or the flow of logic of a business process.
It is equivalent to flowchart and data flow diagram from structured development. The state diagram depict (show)the state of objects as their attributes change from state to . IV.
State and Activity Diagrams State Diagrams Events and States Superstates Activity Diagrams Petri Nets Information Systems Analysis and Design CSC grow to more than a few dozen states. For UML state diagrams, states can be composed into nested states, or superstates.
Such compositions make it possible to. UML state machine, also known as UML statechart, is a significantly enhanced realization of the mathematical concept of a finite automaton in computer science applications as expressed in the Unified Modeling Language (UML) notation.
A UML diagram is a diagram based on the UML (Unified Modeling Language) with the purpose of visually representing a system along with its main actors, roles, actions, artifacts or classes, in order to better understand, alter, maintain, or document information about the system.