Difference between revisions of "T-VEC Tablular Modeler"

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** Verifies that no transitions from a common source state can occur simultaneously.  
 
** Verifies that no transitions from a common source state can occur simultaneously.  
 
The [[Examples|Examples]] section covers some general approaches that take advantage of the latests TTM features, which are important to using modeling from a project and team oriented perspective.
 
The [[Examples|Examples]] section covers some general approaches that take advantage of the latests TTM features, which are important to using modeling from a project and team oriented perspective.
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==Guidelines==
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===Strong Typing===
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Good modeling practices grew out of good programming practices. TTM combined with VGS try to help user attain greater assurance of correctness. Like any variable, strong typing of variables provides greater assurance that the semantics of the relationships where arrays are referenced are correct. An array element ultimately relates to something in the domain, or a particular hardware element that will have a fixed value. If it’s an integer, the integer will be associated with some type of object in the domain (e.g., altitude – the altitude takes on a value that has a range related to what the sensor can represent). Users are encouraged to define all of the types first, then any variable created should use one of those types.
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===Goal-Oriented Behavioral Modeling===
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Use a goal-oriented approach, and work backward by identifying each output (controlled variable or term) of the component.
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*Create a table that assigns the value for each different computed value of the output.
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*Use a condition table to describe relationships between outputs if the relationships are continuous over time (i.e., invariant over time).
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**Work backward, finding all of the conditions that must be TRUE for the function related to the output to be relevant.
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*Use an event table (with mode or modeless) to describe relationships between an output (or term) if the relationships are defined at a specific point in time.
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**Define the events and optional guard conditions that trigger the event.
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*Use a mode transition table (similar to a state machine) to describe relationships between an object if the relationship for a mode is defined for a specific interval of time (set of related system states):
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**Identify the set of modes; define the event associated with each source-to-destination transition.
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If there are common conditions that are related to constraints (i.e., conditions or events) of functions of two or more outputs (or terms), then define a term table that can be referenced in all relevant tables.
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==References==
 
==References==
 
#Constance Heitmeyer.  Using the SCR  Toolset to Specify Software Requirements.  ''Proceedings, Second IEEE Workshop on Industrial Strength Formal Specification Techniques'', Boca Raton, FL, Oct. 19, 1998.
 
#Constance Heitmeyer.  Using the SCR  Toolset to Specify Software Requirements.  ''Proceedings, Second IEEE Workshop on Industrial Strength Formal Specification Techniques'', Boca Raton, FL, Oct. 19, 1998.

Revision as of 14:02, 29 May 2008