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Turning Clockwise: Using UML in the Real-Time Domain. “You mustn’t forget one thing,” the fairy godmother said. “Do not stay past midnight, for when the hour strikes, everything will return to the way it was before. “I promise,” said Cinderella. A Brief History of UML.
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Turning Clockwise: Using UML in the Real-Time Domain “You mustn’t forget one thing,” the fairy godmother said. “Do not stay past midnight, for when the hour strikes, everything will return to the way it was before. “I promise,” said Cinderella.
A Brief History of UML • Rumbaugh joins Booch at Rational Software Corporation. • The UML effort officially starts in October 1994. • The version 0.8 draft of the Unified Method (as it was then called) releases in October 1995. • UML consortium established. • Partners contributing to the UML 1.0 definition include DEC, I-Logix, Intellicorp, IBM, ICON Computing, MCI Systemhouse, Microsoft among others • UML 1.0 was offered for standardization to the Object Management Group (OMG) in January 1997
Real-Time Systems and the Object Paradigm • A real-time system is a software system that maintains an ongoing and timely interaction with its environment.
Requirements for Modeling Real-Time Systems • Infrastructure modeling requirements • Behavior modeling requirements • Structure modeling requirements
Infrastructure Modeling Requirements • Engineering Infrastructure • Networks • Processors • Logical Devices • Scheduling • Timing • Memory Management
Behavior Modeling Requirements • Event-driven • Time-driven
Structure Modeling Requirements • Peer Relationships • Containment Relationships • Layering Relationships
Model • A model is a simplification of reality • Models help us visualize a system as it is or as we want it to be • Models permit us to specify the structure or behavior of a system • Models give us template that guides us in constructing a system • Models document the decisions we have made
Modeling the Engineering Infrastructure • Modeling resources and system services. • Element-to-resource mapping. • Resource-to-value mapping. • Modeling time and timing facilities.
Modeling Real-Time Behavior • Event-driven (reactive) behavior modeling • Time-driven behavior modeling • Object interaction modeling
Modeling Real-Time Structure • Architectural Modeling
Strengths • Strengths • UML stereotypes has enabled to capture real-time concepts and allowed smooth integration of already proven techniques developed in previous generations of real-time methods. • This allows for creation and exploitation of complicated software. • Traditional engineering techniques applied to UML, and hence to real-time systems.
Weaknesses • UML still in its infancy. • Real-time systems model physical reality. • Not always possible to capture the complexities of nature through a modeling language.