CS 426 Senior Projects

1. CS 426Senior Projects Chapter 1: What is UML? Chapter 2: What is UP? [Arlow and Neustadt, 2002] January 26, 2006

2. Outline. • What is UML? • UML history • Why “unified”? • Objects and UML • UML structure • UML building blocks • UML common mechanisms • Architecture

3. .Outline • What is UP? • UP History • UP Axioms • UP Core Workflows • UP Structure • Details on UP Phases

4. What is UML? • The UML (Unified Modeling Language) is a general purpose visual modeling language for systems • Usually associated with OO software systems, but with wider application than that • Incorporates modern best practices in modeling techniques and software engineering • Designed to be supported by CASE tools • It is not a methodology, but a notation that can be used in various software development methodologies • Not tied to any methodology or specific lifecycle; however the preferred method for using UML is the UP (Unified Process)

5. UML History Stages of UML evolution, Fig. 1.2 [Arlow & Neustadt, 2002]

6. UML: Why “unified”? • UML unification encompasses the following: • Development lifecycle: UML can be used from requirements engineering to implementation • Application domains: UML has been used in a profusion of applications, of various types • Implementation languages and platforms: UML is language and platform independent • Development processes: UP is only one of the processes supported by UML • Its own internal concepts: UML is based on a set of concepts that have been applied consistently throughout the notation’s development

7. Objects and UML • The main premise for using UML is that software systems can be modeled as collections of collaborating objects • There are two major, complementary parts in a UML model: • Static structure = constituent objects + their relationships • Dynamic behaviour = functionality provided by the collaborating objects

8. UML Structure There are three main parts in UML structure, as indicated below, Fig. 1.3 [Arlow & Neustadt 2002]

9. UML Building Blocks • UML is composed of three building blocks [Fig. 1.4, Arlow 2002]: • Things, or modeling elements (modeling constructs) • Relationships, that specify how things relate semantically • Diagrams, that provide views into UML models and show collections of interrelated things

10. UML Building Blocks: Things • UML things, or modeling elements, can be classified as: • Structural things, e.g., class, interface, use case, component, node (the “nouns” of a UML model) • Behavioural things, such as interactions and state machines (the “verbs” of a UML model) • Grouping things, e.g. package, which gathers related modeling elements • Annotational things, e.g., the “sticky note” that can be appended to any modeling construct

11. UML Building Blocks: Relationships. • UML relationships indicate how two or more things are interconnected. Relationships apply to structural and grouping things and are of four kinds [Fig. 1.5, Arlow 2002]:

12. UML Building Blocks: .Relationships • Details on UML relationships can be found in other chapters of the book, as follows: [Table 1.1, Arlow & Neustadt, 2002]

13. UML Building Blocks: Diagrams. • A UML model is a repository of all things and relationships created to describe the structure and behavior of the system under development • Diagrams provide views (or windows) into this model • Diagrams also provide mechanisms for entering information into the model • There are nine types of UML diagram, three describe the static structure of the system (the static model), and six describe the dynamic aspects of the system (the dynamic model) [see next slide]

14. UML Building Blocks: .Diagrams The nine types of UML diagram [Fig. 1.6, Arlow & Neustadt, 2002]

15. UML Common Mechanisms • UML has four common mechanisms that are applied consistently, in different contexts, throughout UML [Fig. 1.7, Arlow 2002]

16. UML Common Mechanisms: Specifications • Specifications are textual descriptions of the semantics of UML elements. Example, Fig. 1.8 [Arlow & Neustadt, 2002]

17. UML Common Mechanisms: Adornments • Adornments allow showing more information on UML elements. Example, Fig. 1.9 [Arlow & Neustadt, 2002]

18. UML Common Mechanisms: Common Divisions • Common divisions are ways of thinking about the world (for modeling purposes) • Common divisions in UML are of two types: • Classifiers and instance [see Table 1.2 in the book] • Interface and implementation [see Subsection 1.8.3.2]

19. UML Common Mechanisms: Extensibility There are three types of mechanisms that provide support for UML extensibility, Table 1.3 [Arlow & Neustadt, 2002]

20. Architecture. • The system architecture is “the organizational structure of the system, including its decomposition into parts, their connectivity, interaction, mechanisms and the guiding principles that inform the design of a system.” [Rumbaugh 1998] • There is a typical “4+1 views” architecture of a system defined by UML: • Logical view, captures the vocabulary of the problem domain using classes and objects • Process view, depicts the threads and processes of the system as active classes • Implementation view, shows the physical code base of the system in terms of components • Deployment view, models the physical deployment of components onto computational nodes • Use case view, captures the requirements of the system using a set of use cases. This is the view “+1” to which all other views connect.

21. .Architecture The “4 +1 views” architecture, Fig. 1.11 [Arlow & Neustadt 2002]

22. What is UP? • A software development process (SDP) or software engineering process (SEP) defines the who, what, when, and how of developing software • The Unified Software Development Process(USDP) or, in short, the Unified Process(UP) is an industry standard process created by the authors of UML Fig 2.2, [Arlow 2002]

23. UP History UP evolution, Fig. 2.3 [Arlow & Neustadt, 2002]

24. UP Axioms • Use case and risk driven • Architecture centric • Iterative and incremental • Each iteration contains all the elements of a regular software development project: planning, analysis, design, construction, integration, testing, internal or external release

25. UP Core Workflows. • Requirements: Determining what the system should do • Analysis: Refining and structuring the requirements • Design: Defining system architecture to satisfy requirements • Implementation: Building the software • Testing: Verifying that the implementation is correct A baselineis the result of an iteration, a partially complete version of the final system. An iteration is the difference between two consecutive baselines.

26. .UP Core Workflows Fig.2.5, Arlow 2002

27. UP Structure. Fig.2.6, Arlow 2002

28. .UP Structure Fig.2.7, Arlow 2002

29. UP: Details on Phases. • Each of the four phases of UP (inception, elaboration, construction, transition) has: • A goal • A focus of activity • One or more core workflows • A milestone, with a number of conditions of satisfaction • Details of the above for Inception are given next. The remaining three phases are described in Subsection 2.9 of the textbook

30. UP: .Details on Phases • Inception • Goal: Get the project off the ground • Tasks: • Assess feasibility • Create a strong business case • Capture essential requirements • Identify critical tasks • Focus: Requirements specification and analysis • Milestone: Life-cycle objectives [see conditions of satisfaction n Table 2.1 of the book]