SysML: A Modeling Language for Systems of Systems

1. SysML:A Modeling Language for Systems of Systems Note to Instructor: The material in this slide set is not contained in the 3rd edition of the text book It is planned for the 4th edition.

2. What is SysML? • A graphical modeling language developed by the OMG • A UML profile that presents a subset of UML 2 with extensions • A modeling language for modeling “systems of systems” • Supports the development of complex systems consisting of several systems • Model exchange via XMI • Designed for model-based systems engineering (MBSE)

3. Relationship between SysML and UML • SysML is defined as an extension of a subset of the Unified Modeling Language (UML) using UML's profile mechanism • SysML is MOF compliant All models (MOF) UML models CORBA models (profile) UML 2 .NET models (profile) U2TP (profile) SysML Association Classes SysML models Class Diagrams Use Case Diagrams Requirements Diagrams Parametric Diagrams

4. Model Based Systems Engineering (MBSE) • Model-based systems engineering (MBSE) • The formalized application of modeling to support system requirements, design, analysis, verification, validation activities[INCOSE 2004] • Advantages • Improved communications and knowledge management • Impact analysis of requirements and design changes • More complete representation • A system engineering model contains several models addressing all aspects of the participating systems, hardware as well as software: • Functional model • Behavoral model (Dynamic model) • Structure model (Object model) • Cost model • Organizational model • Development environment, target environment

5. A SysML Model contains several Models Requirements Functional Model Dynamic (Behavior) Model Object (Structure) Model Other Models

6. A SysML System Model containing many Models(ABS Example)

7. SysML Diagram Frames Activity diagram, block diagram, internal block diagram, sequence diagram

8. SysML Diagram Taxonomy Behavior Structure Requirements Parametrics

9. SysML Structural Diagrams Requirements Diagrams

10. Requirements Diagram Elements: Nodes

11. SysML Requirements Diagrams • A SysML requirements diagram depicts the requirements in graphical, tabular or tree structure format • Example: A Requirements Diagram in Visual Paradigm

12. Requirement Node (CASE tool:Visual Paradigm) • A requirement node is a stereotype of a UML Class • It has several attributes • Text: the description of the requirement in natural language • Id: Allows to number the requirement • Source: Location, Stakeholder • Kind: to categorize the requirement into Functional, Performance, Interface • VerifyMethod: Analysis, Demonstration, Inspection, Test • Risk: High, medium, low • Status: Proposed, Approved, Rejected, Deferred, Implemented, Mandatory, Obsolete.

13. Visual Paradigm • University License for Visual Paradigm Standard Edition • Visual Paradigm Tutorials • http://www.visual-paradigm.com/product/vpuml/tutorials.jsp • Requirements Modeling with Visual Paradigm • http://www.visual-paradigm.com/product/vpuml/provides/reqmodeling.jsp • On this URL you also find a tutorial movie about managing SysML requirement diagrams.

14. Adding a Test Case Node (Visual Paradigm)

15. Adding more Requirements Nodes

16. Tabular Format of a Requirements Diagram

18. Dependency Relationships: Linking of Requirements • Requirements can be linked to other requirements • Containment: The requirement contains several sub-requirements • Copy: One requirement is a read-only version of another requirement • Derive: A requirement is derived from another requirement • Requirement elements can also be linked to other model elements (in analysis and design models) • Refine: A model element refines a requirement • Verify: Another model element validates a requirement • Satisfy: Another model element satisfies a requirement • Linking to Use Cases • Linking to Class diagrams • Trace: Any model element that realizes a nonfunctional (performance) requirement.

19. Requirements Diagram Elements: Associations between Nodes • Requirement Containment Relationship

20. Requirements Diagram Elements: Associations between Nodes • Requirement Composition Relationship

21. Requirements Diagram Elements: Associations between Nodes • Requirement Composition Relationship

22. Requirements Diagram Elements: Associations between Nodes • Copy Dependency The text of the Slave requirement is a read-only copy of the text of the Master requirement • Derive Dependency A functional requirement derived from a business need or a test requirement is derived from a functional requirement • Satisfy Dependency Functional Requirement Business Need Example: A use case satisfies a functional requirement.

23. Example of a Copy Dependency (Reuse of Requirements)

24. Example of a Derive Dependency • Based on the requirement specifications from the National Highway Traffic Safety Administration (NHTSA.) • Excerpt of the original requirement text used to create the model:

25. Requirements Diagram Elements: Associations between Nodes • Verify Dependency Example: A test case validates a functional requirement Example: A use case refines a requirement • Refine Dependency Example: A use case can be traced to a requirement. • Trace Dependency

26. Callouts Or: How to avoid “Spaghetti” in Requirements Diagrams Is equivalent to: • TraceCallout • Trace Dependency

27. SysML Structural Diagrams Package Diagrams

28. Package Diagram

29. Organizing a Model by Use Cases Tim Weilkiens, Systems engineering with SysML/UML: modeling, analysis, design‬

30. Organizing a Model by Stakeholders SysML allows provide viewpoints for the stakeholders of a system

31. Package Diagram: Views and ViewPoints • A model usually focuses on one abstraction of the system (analysis, design, cost) • A view provides a perspective that spans multiple abstractions. It includes (subgraphs) of other models • The EngrAnalysis view, for example, includes the organization of the enterprise, the system model, logical design and allocated design • The viewpoint lists the stakeholders and purpose of the view.

32. SysML Structural Diagrams Block Diagrams

33. Blocks: Basic Structural Elements

34. SysML Blocks vs UML Classes • SysML Blocks are based on UML classes • However the do not allow association classes • They distinguish between value properties from part properties • They allow nested connector ends • There are two types of SysML block diagrams • Block definition diagrams (bdd) describing the relationship between blocks (composition, association,…) • Internal block diagrams (ibd) describing the internal structure of a single block in terms of its properties and connectors • Behavior (activity diagrams, use cases) can be allocated to both types of block diagrams.

35. SysML Block Diagrams Internal Block Diagram Block Definition Diagram Anti-Lock Controller

36. Internal Block Diagram: Blocks, Parts, Ports, Connectors and Flows

37. Reference Property vs Part

38. SysML Ports • 2 Port Types • Standard Port (also available in UML) • Specifies a set of operations and/or signals • Typed by a UML interface • Flow Port • Specifies what can flow in or out of a block/part • Typed by a flow specification.

39. Port Notation

40. Links between Requirements and Design

41. Behavioral Diagrams

42. SysML Activities • SysML activity diagram notation is the same as in UML • SysML extensions to support • Continous flow modeling • Alignment of activities with Enhanced Functional Flow Block Diagrams (EFFBD)

43. Activity Diagram Notation (UML, SysML)

44. SysML Activity Diagrams also support Swim Lanes Swimlane TractionDetector Swimlane BrakeModulator

45. SysML Activities can consists of Subactivities Activity Diagram Block Definition Diagram

46. SysML Interactions • SysML sequence diagram notation is also the same as in UML • but SysML does not include timing diagrams and communications diagrams • SysML focuses on black and white box views of interactions with sequence diagrams.

47. Black Box Sequence Diagram (UML, SysML)

48. StartVehicle: Black Box Sequence Diagram

49. StartVehicle: White Box Sequence Diagram

50. SysML State Machines • The same notation as in UML