Introduction to UML: Structural and Use Case Modeling

1. Introduction to UML:Structural and Use Case Modeling

2. Software development process has 5 stages • Requirements analysis and definition: • Establish the application’s goals and constraints in consultation with users • Design: • Establish the system’s architecture • Implementation and unit testing: • Realize the design as a set of programs or program units • Unit testing verifies that each unit meets its specification • Integration and system testing: • Integrate the program units and test as a complete system • Maintenance: • Correct errors, improve implementation, and enhance the system’s services as new requirements are discovered

3. What is the primary driver of software costs? • Most money and effort spent in testing and maintenance • But: 85% of errors are introduced during requirements analysis and design

4. Background • What are object-oriented (OO) methods? OO methods provide a set of techniques for analyzing, decomposing, and modularizing software system architectures In general, OO methods are characterized by structuring the system architecture on the basis of its objects (and classes of objects) rather than the actions it performs • What are the benefits of OO? OO enhances key software quality factors of a system and its constituent components • What is the rationale for using OO? In general, systems evolve and functionality changes, but objects and classes tend to remain stable over time

5. Background Software Quality Factors: Object-oriented techniques enhance key external and internal software quality factors, e.g., 1. External (visible to end-users) (a) Correctness (b) Robustness and reliability (c) Performance 2. Internal (visible to developers) (a) Modularity (b) Flexibility/Extensibility (c) Reusability (d) Compatibility (via standard/uniform interfaces)

6. Background • OOA, OOD, and OOP Object-oriented methods may be applied to different phases in the software life-cycle, e.g., analysis, design, implementation, etc. • OO analysis (OOA) is a process of discovery Where a development team models and under-stands the requirements of the system • OO design (OOD) is a process of invention and adaptation Where the development team creates the abstractions and mechanisms necessary to meet the system's behavioral requirements determined during analysis

7. How to design a registration management system? • Who are users for this system?

8. How to design a registration management system? • Who are users for this system?

9. How to design a registration management system? • What is the role for each user?

10. How to design a registration management system? • What is the role for each user?

11. Difference between XML and UML • What is XML? • What is UML?

12. XML stands for EXtensible Markup Language • XML was designed to describe data and to focus on what data is. (Widely used in database management) • HTML was designed to display data and to focus on how data looks. (used on WWW) • What is XML?

13. UML stands for Unified Modeling Language • In the field of software engineering, UML is a standardized specification language for object modeling. • UML is a general-purpose modeling language that includes a graphical notation used to create an abstract model of a system, referred to as a UML model. • What is UML?

14. What is UML? • Is a language. It is not simply a notation for drawing diagrams, but a complete language for capturing knowledge(semantics) about a subject and expressing knowledge(syntax) regarding the subject for the purpose of communication. • Applies to modeling and systems. Modeling involves a focus on understanding a subject (system) and capturing and being able to communicated in this knowledge. • It is the result of unifying the information systems and technology industry’s best engineering practices (principals, techniques, methods and tools).

15. Unified Modeling Language (UML) • used for both database and software modeling • version 1.1 was adopted in November 1997 by the Object Management Group (OMG) as a standard language for object-oriented analysis and design • Initially based on a combination of the Booch, OMT (Object Modeling Technique) and OOSE (Object-Oriented Software Engineering) methods, UML was refined and extended by a consortium of several companies, and is undergoing minor revisions by the OMG Revision Task Force. • Ivar Jacobson is known as the father of Use Cases.

16. 1. Structural Modeling with UML Structural model: a view of an system that emphasizes the structure of the objects, including their classes, relationships, attributes and operations. 2. Use Case Modeling with UML use case model: a view of a system that emphasizes the behavior as it appears to outside users. A use case model partitions system functionality into transactions (‘use cases’) that are meaningful to users (‘actors’). • Topics on UML

17. What you will learn: • what the UML is and what is it not • UML’s basic constructs, rules and diagram techniques • how the UML can model large, complex systems • how the UML can specify systems in an implementation-independent manner • how UML, XML Metadata Interchange (XMI) and Meta Object Facility (MOF) can facilitate metadata integration

18. Quick Tour • Why do we model? • Why do we develop the UML? • Foundation elements • Unifying concepts • Language architecture • Relation to other OMG technologies

19. Why do we model? • Modeling is a way of thinking about the problems using models organized around the real world ideas. • A modeling method comprises a language and also a procedure for using the language to construct models. • modeling is the only way to visualize your design and check it against requirements before your crew starts to code. 

20. Why do we model? • Provide structure for problem solving • Experiment to explore multiple solutions • Furnish abstractions to manage complexity • Reduce time-to-market for business problem solutions • Decrease development costs • Manage the risk of mistakes

21. The Challenge Tijuana “shantytown”: http://www.macalester.edu/~jschatz/residential.html

22. The Vision Fallingwater: http://www.adelaide.net.au/~jpolias/FLW/Images/FallingWater.jpeg

23. Why do we model graphically? • Graphics reveal data. • Edward TufteThe Visual Display of Quantitative Information, 1983 • 1 bitmap = 1 megaword. • Anonymous visual modeler

24. Quick Tour • The UML is a graphical language for • specifying • visualizing • constructing • documenting the artifacts of software systems • Added to the list of OMG adopted technologies in November 1997 as UML 1.1 • Minor revisions are in UML 1.2 (1998), 1.3 (1999), 1.4 (2001), and 1.5 (2003). • Major revision is UML 2.0, completed in 2005. The current standard.

25. UML Goals • Define an easy-to-learn but semantically rich visual modeling language • Unify the Booch, OMT, and Object modeling languages • Include ideas from other modeling languages • Incorporate industry best practices • Address contemporary software development issues • scale, distribution, concurrency, executability, etc. • Provide flexibility for applying different processes • Enable model interchange and define repository interfaces

26. OMG UML Evolution 1970: First object-oriented languages (Simula-67, Smalltalk). 1980: More than 50 different OOAD languages cause the users trouble to find complete and appropriate tools. 1992: New iterations of methods appear. Booch ‘93, OOSE (Jacobson), OMT-2 (Rumbaugh) 1995: Unification, UML 0.9 by Booch, Rumbaugh 1997: Standardization, UML 1.1 by Booch, Rumbaugh, Jacobson. Object Management Group (OMG) adapts UML as OOAD standard 1999: Evolving standard in version 1.3 2005: Major revision in version 2.0

27. OMG UML Evolution

28. OMG UML Specification • UML Summary • UML Semantics • UML Notation Guide • UML Example Profiles • Software Development Processes • Business Modeling • Model Interchange • Model Interchange Using XMI • Model Interchange Using CORBA IDL • Object Constraint Language

29. Focus: the Language • language = syntax + semantics • syntax = rules by which language elements (e.g., words) are assembled into expressions (e.g., phrases, clauses) • semantics = rules by which syntactic expressions are assigned meanings • UML Notation Guide – defines UML’s graphic syntax • UML Semantics – defines UML’s semantics

30. Foundation Concepts • Building blocks • Well-formed rules

31. Building Blocks • The basic building blocks of UML are: • model elements (classes, interfaces, components, use cases, etc.) • relationships (associations, generalization, dependencies, etc.) • diagrams (class diagrams, use case diagrams, interaction diagrams, etc.) • Simple building blocks are used to create large, complex structures • cf. elements, bonds and molecules in chemistry • cf. components, connectors and circuit boards in hardware

32. Diagram: Class View

33. Diagram: Instance View

34. Well-Formed Rules • Well-formed: indicates that a model or model fragment adheres to all semantic and syntactic rules that apply to it. • UML specifies rules for: • naming • scoping • visibility • integrity • execution • However, during iterative, incremental development it is expected that models will be incomplete and inconsistent.

35. Well-Formed Rules (cont’d) • Example of syntactic rules: Class • Basic Notation: A class is drawn as a solid-outline rectangle with three compartments separated by horizontal lines. • Presentation Option: Either or both of the attribute and operation compartments may be suppressed. • Example of syntactic guideline: Class • Style Guideline: Begin class names with an uppercase letter.

36. Unifying Concepts • class-instance dichotomy • e.g., an object is an instance of a class ORa class is the classifier of an object • specification-realization dichotomy • e.g., an interface is a specification of a class ORa class is a realization of an interface • analysis-time vs. design-time vs. run-time • modeling phases (“process creep”) • usage guidelines suggested, not enforced

37. Structural Modeling • What is structural modeling? • Core concepts • Diagram tour • When to model structure • Modeling tips

38. What is structural modeling? • Structural model: a view of an system that emphasizes the structure of the objects, including their classes, relationships, attributes and operations.

39. Structural Modeling: Core Elements

40. Structural Modeling: Core Elements(cont’d) ¹ An extension mechanism useful for specifying structural elements.

41. Structural Modeling: Core Relationships

42. Structural Modeling: Core Relationships(cont’d)

43. Structural Diagram Tour • Show the static structure of the model • the entities that exist (e.g., classes, interfaces, components, nodes) • internal structure • relationship to other entities • Do not show • temporal information • Kinds • static structural diagrams • class diagram • object diagram • implementation diagrams • component diagram • deployment diagram

44. Static Structural Diagrams • Shows a graph of class elements connected by static relationships. • kinds • class diagram: class view • object diagram: instance view

45. Classes

46. Classes: compartments with names

47. Classes: method body

48. Types and Implementation Classes

49. Interfaces: Shorthand Notation

50. Interfaces: Longhand Notation