BirthME, Doulas

In the diagram that represents the composite state or state region, drag a Shallow History or Deep History shape onto the drawing page.. Use Transition shapes to indicate the transitions that come from outside the state region. For example, the hierarchical state machine representing the pocket calculator (Figure 3) avoids repeating the transitions Clear and Off in virtually every state. The triggers and the subsequent effect of a transition may be notated either textually according For example, if a system is in the "on" superstate (Figure 3), it may be the case that it is also in either "operand1" substate OR the "operand2" substate OR the "opEntered" substate OR the "result" substate. The name tab is a rectangle, usually resting on the outside of the top side of a state. The state machine that A transition to the enclosing state Do Activity – Action performed on entry to state 4.
The use of entry and exit actions is preferable to placing an action on a transition because it avoids repetitive coding and improves function by eliminating a safety hazard; (heater on while door open). Simple composite state Serving Customer has two substates.

dashed lines to divide it into regions. outgoing transition may be presented as a state symbol with a list of the state names and an outgoing transition symbol In that case, the composite state may be represented by a simple state graphic with a special "composite" icon, The same state machine may be a submachine more Once generated, the event instance goes through a processing life cycle that can consist of up to three stages. Inherited states are drawn with dashed lines or gray-toned lines. Any state enclosed …

UML statecharts also introduce the complementary AND-decomposition. The coupling occurs through the guard conditions attached to transitions, as shown in Figure 2. The left operand is placed inside the diamond-shaped symbol and the rest of the guard expressions From the previous discussion, recall the two states of the main keypad already identified: "default" and "caps_locked" (see Figure 1). Construction of a class always starts at the very root of the class hierarchy and follows through all inheritance levels down to the class being instantiated. The "hiding" is a matter of graphical convenience and has no semantic significance in terms of access restrictions. A transition is a directed relationship between a source Alternatively, the “bracket” notation can also be used for the transition oriented notation. As shown in Figure 5, it could be specified that the exit action from "heating" disables the heater, the entry action to "door_open" lights up the oven lamp, and the exit action from "door_open" extinguishes the lamp. Avoiding repetition allows the growth of HSMs to remain proportionate to growth in system complexity. The complete state space of the keyboard in the standard decomposition is therefore the Note that if the orthogonal regions are fully independent of each other, their combined complexity is simply additive, which means that the number of independent states needed to model the system is simply the sum In most real-life situations, orthogonal regions would be only approximately orthogonal (i.e. Initial pseudostate transitions to Waiting for User Input state The exact syntax of action and guard expressions isn't defined in the UML specification, so many people use either structured English or, more formally, expressions in an implementation language such as Nevertheless, most of the statecharts semantics are heavily biased toward graphical notation. Obviously, these features are very interesting to software developers, because only they make the whole state machine approach truly applicable to real-life problems. with the name associated with it.

unless there are choice points along one or more of the paths. Due to the phenomenon known as state and transition explosion, the complexity of a traditional FSM tends to grow much faster than the complexity of the system it describes. Choice based on guards applied to the value inside diamond The target state configuration is completely entered only after encountering a leaf state that has no initial transitions. Composite state Serving Customer with decomposition hidden. Consequently, the order of execution of entry actions must always proceed from the outermost state to the innermost state (top-down).