1. Introduction to UML: Structural &Use Case Modeling

2. 1. Software Engineering Tour

3. 5 stages of software development process
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

4. What is the primary driver of software costs?
Most money and effort (82%) spent in testing and maintenance
But: 85% of errors are introduced during requirements analysis and design 3% 8% 7%
15%
67%
Requirements %
Design %
Implementation -- 7%
Testing %
Maintenance %
Software Cost

5. Waterfall model of software process
A sequential software development model (a process for the creation of software) in which development is seen as flowing steadily downwards (like a waterfall) through the phases of requirements analysis, design, implementation, testing (validation), integration, and maintenance.

6. Waterfall model
Progress flows from the top to the bottom, like a waterfall.

7. V model of software process
An extension of the waterfall model. Instead of moving down in a linear way, the process steps are bent upwards after the coding phase, to form the typical V shape. The V-Model demonstrates the relationships between each phase of the development life cycle and its associated phase of testing.

8. V model

9. Prototyping of software process
This model adds prototyping as sub-process
A prototype is a partially developed product that enables customers and developers to examine some aspect of a proposed system and decide if it is suitable for a finished product
Why add prototypes to the life cycle?
Used to explore the risky aspects of the system:
Risk of developing the “wrong” system (what customer doesn’t want), can be a user interface without functionality
Other technical risks – e.g. performance, using a new technology, alternative algorithms, etc.
Prototype may be thrown away or evolve into product

10. Rational Unified Process (RUP)
Developed by “three amigos” at Rational Software (IBM)
Grady Booch, Ivar Jacobson, and Jim Rumbaugh
Unified Modeling Language (UML) is a set of graphical and linguistic notations for modeling systems, not a process or method
The three amigos also developed Rational Unified Process (RUP)
You don’t have to use RUP to use UML
Interestingly different from the traditional waterfall model
Highly iterative and incremental process
Software product is not released in one big bang at end of project
Instead, developed and released in pieces (prototypes, partial releases, beta, etc.)

11. How do traditional stages iterate?
Workflows look traditional, but they iterate in four phases

12. What does iteration imply about RUP?
How can iterations reduce risk or reveal problems?

13. 2. UML Modeling Basics

14. What is UML? 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.

15. Why UML?

16. 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).

17. 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.

18. Topics on UML
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’).

19. 2.1 Structural Modeling What is structural modeling? Core elements
Core relationships
Structural diagram

20. 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.

21. Structural Modeling: Core Elements

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

23. Structural Modeling: Core Relationships

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

25. 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

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

27. Class/Object

28. Class: compartments with names

29. Class: method body

30. Types and Implementation Classes

31. Interfaces: Shorthand Notation

32. Interfaces: Longhand Notation

33. Associations

34. Composition

35. Generalization

36. Dependencies

37. Derived Attributes and Associations

38. Constraints and Comments

39. Implementation Diagrams
Show aspects of model implementation, including source code structure and run-time implementation structure
Kinds
component diagram
deployment diagram

40. Component Diagram
Shows the organizations and dependencies among software components
Components may be
specified by classifiers (e.g., implementation classes)
implemented by artifacts (e.g., binary, executable, or script files)

41. Component Diagram Example
Order System component depends both on the Customer Repository and Inventory System components

42. Deployment Diagram
Models the physical deployment of artifacts (software components) on nodes (hardware components)
Deployment diagrams are used to show which components may run on which nodes

43. Deployment Diagram Example
Deployment Diagram of Order Management System
(a web based application is deployed in a clustered environment using server 1, 2, and 3.)

44. 2.2 Use Case Modeling What is use case modeling? Core elements
Core relationships
Diagram tour
Example: Online HR System

45. What is use case modeling?
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’).

46. Use Case Modeling: Core Elements

47. Use Case Modeling: Core Relationships
<<extend>>

48. Use Case Modeling: Core Relationships (cont’d)
<<include>>

49. Use Case Diagram Tour Shows use cases, actor and their relationships
Use case internals can be specified by text and/or interaction diagrams
Kinds
use case diagram
use case description

50. College Registration System
Use Case Diagram
College Registration System

51. Example: Online HR System

52. Online HR System: Use Case Relationships

53. Online HR System: Update Benefits Use Case
Actors: employee, employee account db, healthcare plan system, insurance plan system
Preconditions:
Employee has logged on to the system and selected ‘update benefits’
option
Basic course
System retrieves employee account from employee account db
System asks employee to select medical plan type; include Update
Medical Plan
System asks employee to select dental plan type; include Update Dental
Plan …
Alternative courses
If health plan is not available in the employee’s area the employee is
informed and asked to select another plan...

54. Ideas to Take Away
UML is effective for modeling large, complex software systems
It is simple to learn for most developers, but provides advanced features for expert analysts, designers and architects
It can specify systems in an implementation-independent manner
Structural modeling specifies a skeleton that can be refined and extended with additional structure and behavior
Use case modeling specifies the functional requirements of system in an object-oriented manner

55. 3. UML Modeling Tools

56. Violet UML Editor Tool

57. Thank You !