CS 426 Senior Projects

1. CS 426Senior Projects Chapter 1: What is UML? Chapter 2: What is UP? [Arlow and Neustadt, 2005] January 24, 2011

2. Outline. • What is UML? • UML history • MDA – the future of UML • 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, 2005]

6. MDA – the future of UML • Model driven architecture (MDA) is based on the idea that models can drive the production of executable software environments

7. 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

8. Objects and UML • The main premise for using UML is that software systems can be modeled as collections of interacting 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

9. UML Structure There are three main parts in UML structure, as indicated below, Fig. 1.4 [Arlow & Neustadt 2005]

10. UML Building Blocks • UML is composed of three building blocks [Fig. 1.5, Arlow 2005]: • 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

11. 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

12. UML Building Blocks: Relationships • UML relationships indicate how two or more things are interconnected. Relationships apply to structural and grouping things and are as follows [Table 1.1, Arlow & Neustadt 2005]:

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 13 types of UML diagram, 6 of them describing the static structure of the system (the static model), and 7 the dynamic aspects of the system (the dynamic model) [see next slide]

14. UML Building Blocks: .Diagrams. Types of UML diagrams [Fig. 1.6, Arlow & Neustadt, 2005]

15. UML Building Blocks: ..Diagrams UML syntax for diagram [Fig. 1.7, Arlow & Neustadt, 2005] & diagram with implied frame [Fig. 1.8, Arlow & Neustadt, 2005]

16. UML Common Mechanisms • UML has four common mechanisms that are applied consistently, in different contexts, throughout UML [Fig. 1.9, Arlow 2005]

17. UML Common Mechanisms: Specifications • Specifications are textual descriptions of the semantics of UML elements. Example, Fig. 1.10 [Arlow & Neustadt, 2005]

18. UML Common Mechanisms: Adornments • Adornments allow showing more information on UML elements. Example, Fig. 1.11 [Arlow & Neustadt, 2005]

19. 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 instances [see Table 1.2 in the book] • Interface and implementation

20. UML Common Mechanisms: Extensibility There are three types of mechanisms that provide support for UML extensibility, Table 1.3 [Arlow & Neustadt, 2005]

21. 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.

22. .Architecture The “4 +1 views” architecture, Fig. 1.13 [Arlow & Neustadt 2005]

23. 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 & Neustadt 2005]

24. UP History UP evolution, Fig. 2.3 [Arlow & Neustadt, 2005]

25. UP Founders • Grady Booch • Video: why engineering? • Video: the promise, the limits, the beauty of software • Video: smarter products for a smarter planet • Ivar Jacobson • Jim Rumbaugh

26. 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

27. 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.

28. .UP Core Workflows Fig.2.5 [Arlow & Neustadt, 2005]

29. UP Structure. Fig.2.6 [Arlow & Neustadt, 2005]

30. .UP Structure Fig.2.7 [Arlow & Neustadt, 2005]

31. 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

32. 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 in Table 2.1 of the book]