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Difference between revisions of "Requirements-Dynamic Model"

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'''Interaction'''
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===Interaction===
 
Interactions are at the heart of messaging. The formal definition of an interaction is:  
 
Interactions are at the heart of messaging. The formal definition of an interaction is:  
  
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The Wrapper types refer to the Transmission Wrapper and the Trigger Event Control Act Wrapper. The Trigger Event Control Act wrapper is a conditional wrapper which contains domain specific administrative information related to that which triggered the interaction. This type of wrapper does not appear with HL7 messages where there is no additional context that is needed to be exchanged dynamically, or with HL7 messages that are carrying commands to coordinate the operation of message handling services.  
 
The Wrapper types refer to the Transmission Wrapper and the Trigger Event Control Act Wrapper. The Trigger Event Control Act wrapper is a conditional wrapper which contains domain specific administrative information related to that which triggered the interaction. This type of wrapper does not appear with HL7 messages where there is no additional context that is needed to be exchanged dynamically, or with HL7 messages that are carrying commands to coordinate the operation of message handling services.  
  
'''Trigger Event'''
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===Trigger Event===
 
A trigger event is an explicit set of conditions that initiate the transfer of information between system components (application roles). It is a real-world event such as the placing of a laboratory order or drug order. The trigger event must be systematically recognizable by an automated system.  
 
A trigger event is an explicit set of conditions that initiate the transfer of information between system components (application roles). It is a real-world event such as the placing of a laboratory order or drug order. The trigger event must be systematically recognizable by an automated system.  
  
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In the v3 standard, most trigger events will be a specifiedType, from the following list:
 
In the v3 standard, most trigger events will be a specifiedType, from the following list:
 
  
 
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Most trigger events are State-Transition based and will be encountered when reading the dynamic message model information defined to support a particular message interaction. Some trigger events may be based on more than one state transition, which are assumed to occur simultaneously. In some cases, trigger events may not fall into any of the three categories defined in the above list. In these cases, Unspecified will appear as the Type. The trigger event Type, when specified, affects the responsibilities of the interactions initiated by that trigger event.  
 
Most trigger events are State-Transition based and will be encountered when reading the dynamic message model information defined to support a particular message interaction. Some trigger events may be based on more than one state transition, which are assumed to occur simultaneously. In some cases, trigger events may not fall into any of the three categories defined in the above list. In these cases, Unspecified will appear as the Type. The trigger event Type, when specified, affects the responsibilities of the interactions initiated by that trigger event.  
  
'''State Machine'''
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===State Machine===
 
The behavioral aspect of a class is defined in a state diagram associated with a class in an information model. State diagrams, which show all of the potential states for a class, are developed for classes that are the central subject of an interaction. These classes are called subject classes. Interactions are sometimes motivated by changes in the state of a subject class. For example, Act may be identified as a subject class. The vocabulary domain for the Act.status_cd declares the defined states for the Act. Those states include Active, Suspended, Cancelled, Complete, and Aborted. A state diagram depicts the allowable class states with a box labeled with the name of the state. Changes in state are called state transitions and are depicted in the diagram by a line with a arrowhead showing the direction of the transition. An example of a state transition might be the change in the state of an Act from Active to Complete. The change in state (state transition) is associated with a trigger event that causes the transition. The trigger event in this example might be the fulfillment of an order. An order is a special type of Act. The transition from an Active order to a Completed order is triggered by the fulfillment of the Order. The state diagram depicts the states, trigger event, and state transitions of interest.  
 
The behavioral aspect of a class is defined in a state diagram associated with a class in an information model. State diagrams, which show all of the potential states for a class, are developed for classes that are the central subject of an interaction. These classes are called subject classes. Interactions are sometimes motivated by changes in the state of a subject class. For example, Act may be identified as a subject class. The vocabulary domain for the Act.status_cd declares the defined states for the Act. Those states include Active, Suspended, Cancelled, Complete, and Aborted. A state diagram depicts the allowable class states with a box labeled with the name of the state. Changes in state are called state transitions and are depicted in the diagram by a line with a arrowhead showing the direction of the transition. An example of a state transition might be the change in the state of an Act from Active to Complete. The change in state (state transition) is associated with a trigger event that causes the transition. The trigger event in this example might be the fulfillment of an order. An order is a special type of Act. The transition from an Active order to a Completed order is triggered by the fulfillment of the Order. The state diagram depicts the states, trigger event, and state transitions of interest.  
  

Revision as of 17:35, 19 October 2009