Nested States

The Nested States pattern describes a Block or other element that has a number of States one or more of which themselves have states (sub states). The pattern allows these states to be displayed on the same diagram.

Figure 1. A State Machine diagram showing nested states in one of the states.
Discussion
The purpose is to allow Systems Engineers to create a visual representation of two (or more) levels of State transitions on a single diagram. 

This representation is often useful when conducting a walk-through of the transitions to understand the owning element's behavior or when placing the nested states on the same diagram makes it easier to understand the transitions between states without the need to click through to a composite diagram.

·	Rename the States and Transitions in the diagram to suit your initiative.
New States and other elements and connectors can be dragged onto the diagram from the Toolbox or the Project Browser.

The following is a list of some of the next steps available when applying the pattern.
·	Create an executable State Machine from the diagram.
Show how States in this State Machine interact with States in other State Machine constructed for other elements in the model.

Useful Workspace Layouts Core | Core Modeling, Wide View
Reference
The following help topics will assist you learn about how to work with this pattern.
State Machines
Working with Diagrams
Changing Element Appearance
Changing Diagram Layout

The following tools are useful when working with this pattern.
Specification View
The Specification View can be used as a way of working with the Components and Interfaces particularly when there are a large number of elements as is typically the case when describing a system of any appreciable size. For more details see the Specification View help topic
Hand Drawn and Whiteboard Diagrams
The Hand Drawn and Whiteboard Mode are display options available for any diagram that changes a system-drawn diagram to appear as though it was drawn by hand and, optionally, hand drawn on a whiteboard. It is a powerful device to engage an audience by presenting the diagram in a rough and more immediate style giving the impression that it is just a sketch that can be changed. For more details see the Hand Drawn and Whiteboard Mode help topic.
Alternate and Images for Diagram Elements
Most standard elements allow an alternate image to be defined for an element that will be used in place of the graphical notation for the element either on a selected diagram or as a default on all diagrams. For more details see the Using the Image Manager help topic.
Document Generator
The Document Generator is a powerful facility in Enterprise Architect that allows a Database Engineer or other stakeholder to create high quality corporate or technical documentation directly from the model, suitable for internal or external audiences. For more details see the Documentation help topic or the more general topic on Model Publishing.

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