Object management organization OMG The decision is right UML2.0 On the basis of reuse and extension , A new system modeling language is proposed ——SysML(Systems Modeling Language), As a standard modeling language for systems engineering . and UML The modeling language used in unified software engineering is the same ,SysML The purpose of this paper is to unify the modeling language used in system engineering .
SysML It is the structural model of the system , Behavior model , Requirements model and parameter model define semantics . The structural model emphasizes the hierarchy of the system and the interconnection between objects , Includes classes and assemblies . Behavior model emphasizes the behavior of objects in the system , Including their activities , Interaction and state history . The requirement model emphasizes the traceability between requirements and the satisfaction of design to requirements . The parametric model emphasizes the constraint relationship between the attributes of a system or component .SysML It provides complete semantics for model representation .
and UML equally ,SysML The structure of the language is also based on the four level meta model structure ： element - Metamodel , Metamodel , Models and user objects . element - The metamodel layer has the highest level of abstraction , Is the model that defines the meta model description language , It provides basic concepts and mechanisms for defining elements and mechanisms of meta model . Metamodel is meta - Examples of metamodels , A model that defines a model description language . The meta model provides various packages to express the system , The definition type of the model element , Tag values and constraints, etc . A model is an instance of a metamodel , A model for defining domain specific description languages . A user object is an instance of a model . Any complex system is the concrete object of communication between users , The purpose is to realize the function and performance of complex system .
SysML The graphic representation of is SysML Visual representation of , Is a tool for modeling systems .SysML Nine basic graphics are defined to represent all aspects of the model . It is divided from different description angles of the model , The nine basic figures are divided into four categories ： Structure diagram (Structure Diagram), Parameter diagram (Parametric Diagram), Demand graph (Requirement Diagram) And behavior diagram (Behavior Diagram) . Structure diagrams include class diagrams (Class Diagram) And assembly drawings (Assembly Diagram), Behavior diagrams include activity diagrams (Activity Diagram), Sequence diagram (Sequence Diagram), Time chart (Timing Diagram), State machine diagram (State Machine Diagram) And use case diagrams (Use Case Diagram).