Object Oriented Analysis and Design Using the UML OOADv4.2 Instructor Notes Object Oriented Analysis and Design Using the UML Analysis and Design Overview Module 5 - Analysis and Design Overview

Objectives: Analysis and Design Overview OOADv4.2 Instructor Notes Objectives: Analysis and Design Overview Review the key analysis and design terms and concepts Introduce the analysis and design process, including roles, artifacts and workflow Understand the difference between analysis and design Note that the details of each of the Analysis and Design activities will be covered later. Present a context for the detailed analysis and design activities. Module 5 - Analysis and Design Overview

Analysis and Design in Context OOADv4.2 Instructor Notes Analysis and Design in Context Inception Elaboration Construction Transition Review the Rational Unified Process Framework and the relationship of the Analysis and Design workflow to the other workflows in the Rational Unified Process Framework. The Rational Unified Process Framework was introduced in the Introduction to RUP Module. Highlight what part of the overall process we will be concentrating on (analysis and design activities in an early elaboration iteration). Requirements Analysis & Design Test Configuration & Change Mgmt Management Environment Preliminary Iteration(s) Iter. #1 Iter. #2 Iter. #n Iter. #n+1 Iter. #n+2 Iter. #m Iter. #m+1 The purposes of Analysis and Design are: To transform the requirements into a design of the system to-be. To evolve a robust architecture for the system. Note: Analysis and Design taken ‘together.’ WHY????? Olden days versus Modern Times….. Module 5 - Analysis and Design Overview

Analysis and Design Overview OOADv4.2 Instructor Notes Analysis and Design Overview Input Artifacts – from Requirements Workflow Design Model If a separate analysis model is desired, then an Analysis Model would be listed as a separate artifact (in addition to the Design Model). Use-Case Model Ultimately, we wish to produce a Design Model Analysis and Design Architecture Document Glossary Supplementary Specification Data Model Module 5 - Analysis and Design Overview

Analysis and Design Overview (continued) Design model is an abstraction of source code and serves as the blue print for Construction. Design Model consists of Design Classes structured into Design packages Design Model also contains descriptions as to how objects of these design classes interact to perform Use Cases (Use Case Realizations) Class diagrams and Interaction Diagrams do this for us…

Analysis and Design Overview (continued) Design activities are centered around the notion of an architecture. Production and validation of this architecture is the main focus of early design iterations. Architectural design is found in Elaboration. Architecture is represented by a number of architectural views that capture the major structural design decisions. Architectural views are the abstractions or simplifications of the entire design, in which important characteristics are made more visible by leaving details aside.

Analysis and Design Overview (continued) We will create an Analysis Model as the first part of Analysis and Design. We create Analysis Classes from Use Cases Our Design Model will take the artifacts from Analysis Modeling (analysis classes) and create Design classes (static view) and Use Cases realizations (dynamic view) – showing how objects collaborate in ‘realizing’ each use case.

Analysis & Design Overview Topics OOADv4.2 Instructor Notes Analysis & Design Overview Topics Key Concepts – Get a common vocabulary Recall: Use Cases are developed using the language (jargon) of the end-user / other stakeholders…. Have a Glossary / Domain Model already… Analysis & Design Workflow Overview Module 5 - Analysis and Design Overview

Analysis Versus Design OOADv4.2 Instructor Notes Analysis Versus Design Difference is on emphases Analysis Focus on understanding the problem Idealized design (Generalized) Behavior System structure Functional requirements Lip service for non-functional requirements A small model Design Focus on understanding the solution Operations and Attributes Performance Close to real code Object lifecycles Non-functional requirements A large model An instructor once said: “Analysis Vs. Design is important because of the mind-set. If you tried to manage all of the analysis and design issues in one go, your brain would explode on all but the most trivial developments. It’s just too much to take in, comprehend, and model in one go. So I mentally switch “OK, analysis - problem domain - don’t care about memory, persistence, databases, language, etc”. “Right now it’s design and I do care about all those things - but now I can stop thinking (too a degree) about trying to understand the business domain.” It’s about managing the 7+/-2 things I can think about in one go. It also separates out the skills (a bit).” Another instructor once said: “analysis is the study of and eventual comprehension of “some thing” [the problem space]. But to understand it, we must invent some entities to hold onto the thing that we have just grasped - this inventive process is design. That is, human cognitive thinking is actually interwoven analysis/design and any attempt to separate them is really only an idealization. Therefore, if I try to apply two separate “steps” in the production of, say, a class diagram [and call those steps A and then D], I will introduce ambiguity into my process because cognitive process forces one to “produce a solution” in order to “understand a problem” - that D is necessary to have any results from A.” Think of analysis as an idealized design step - where we ignore several complicating issues. This can turn into a religious debate. Analysis: understanding the problem; develop a visual model of What you are trying to build Module 5 - Analysis and Design Overview

Goal of Analysis Understand the problem; try to build a visual model of what you are trying to do independent of implementation or technology concerns. Focus on translating the functional requirements into software concepts Note: Nothing in Use Cases says ‘Objects.’ We are capturing Requirements! (the Whats!) Get rough cut at objects that from our system but focusing on behavior and therefore encapsulation. Some authors (and me) include an Analysis Model here – sometimes considered first part of Design (preliminary design); sometimes merely considered part of Design itself. In some circles, there is ‘only’ Requirements and then Design… Many ‘organizations’ tailor activities to their own ‘interpretations.’

Goal of Design Refine Analysis Model with a goal of creating a Design Model that will facilitate our moving “quickly and seamlessly” into coding. (Morph Analysis Classes into Design classes and more!) Design Model will help us adapt to implementation (and deployment) environments. Note that design model elements are abstractions of code / implementation. Constitute the ‘solution space’

Analysis  Design  Solution In modeling, we will start with an object model that resembles the real world (analysis) then, Find more abstract (but more fundamental) solutions to a more general problem (design)

Analysis and Design is not Top-Down or Bottom-Up OOADv4.2 Instructor Notes Analysis and Design is not Top-Down or Bottom-Up Use cases come in from the left and define a middle level Analysis Classes are not defined in a top-down or bottom-up pattern; they are in the middle . Top Down Subsystems Bottom Up Use Cases Defining Subsystems is moving ‘up;’ defining design classes is moving down. Must travel all paths to get system right. Analysis Classes Design Classes Simply NOT Top Down… Module 5 - Analysis and Design Overview

Design Model A Use Case Realization describes how a particular use case is implemented in the design model in terms of collaborating objects.  In the RUP, each use case has a use case realization!! A Use-Case Realization ties use cases from the use-case model and ‘analysis classes’ to design classes and related design entities and relationships of a Design Model. A Use-Case Realization specifies what classes must be built, how they collaborate (relationships, dependencies…), and the messages passed between objects necessary to implement each use case

What is a Use-Case Realization? OOADv4.2 Instructor Notes What is a Use-Case Realization? A use-case realization in the design model can be traced to a use case in the use-case model. A “realization relationship” is drawn from the use-case realization to the use case it “realizes.” If you consider use cases and scenarios to be black box descriptions of the system, then the use-case realizations are the associated white box descriptions. Use-case realizations are introduced here because use-case realizations may be mentioned when providing the overview of the analysis and design workflow (the developing of use-case realizations is the main goal of Use-Case Analysis and the refinement of these use case realizations is the main goal of Use-Case Design). The use case realizations are identified in Architectural Analysis, initially developed in Use-Case Analysis and then refined in Use-Case Design. The Rational Unified Process includes templates for the the use-case realization, as well as the use-case realization icon. In Rose, you cannot draw realizations between use cases, so a stereotyped association must be used instead. In Rose, use-case realizations are modeled as stereotyped use cases. This is discussed in more detail in the Use-Case Analysis module. Use-Case Model Design Model Use Case Use-Case Realization (realizes relationship) Sequence Diagrams Collaboration Diagrams Use Case Class Diagrams A use case realization can be represented using a set of diagrams which model the context of the collaboration – class diagrams,and the interactions of these collaborations – collaboration and sequence diagrams. Module 5 - Analysis and Design Overview

Software Architecture: The “4+1 View” Model OOADv4.2 Instructor Notes Software Architecture: The “4+1 View” Model Discuss the 4+1 views. These are covered in detail in the Rational Unified Process. The 4+1 model is introduced here and because it is important for the students to see how the views fit together up front, in order to set context. The individual views are addressed in the specific architecture modules: The Logical view will be discussed in the Architectural Analysis and Architectural Design module. The Process View will be discussed in the Describe Concurrency module. The Deployment View will be discussed in the Describe Distribution module. The Implementation View will be discussed briefly in the Architectural Design module; however, the Implementation View is developed during Implementation and is thus considered out of scope for this analysis and design course. Logical View Implementation View End-user Functionality Analysts/Designers Structure Programmers Software management Use-Case View Process View Deployment View Performance Scalability Throughput System integrators System engineering System topology Delivery, installation communication This diagram describes how Rational Software Corporation models software architecture Projects have multiple stakeholders – each with unique concerns and views. Rational has defined the 4+1 architectural model – a series of simplified descriptions (abstractions) from particular perspectives – omitting entities not relevant to this view. A project may document all views, a subset, or additional views. But EACH VIEW is complete from the perspective of specific stakeholder(s). Module 5 - Analysis and Design Overview

Analysis & Design Overview Topics OOADv4.2 Instructor Notes Analysis & Design Overview Topics Key Concepts Analysis & Design Workflow Overview Module 5 - Analysis and Design Overview

Analysis and Design Workflow OOADv4.2 Instructor Notes Analysis and Design Workflow Architect Designer Architectural Analysis Architecture Reviewer Review the Design Use-Case Describe Concurrency Distribution Class Subsystem Design Walk the students through the workflow diagram, reviewing the meaning of the representational icons (e.g., workers, activities, etc.). Activities can be considered operations on the workers. The order shown is not the only order in which the activities can be executed. It is an idealized picture. Note the emphasis on architecture -- how it is developed first and then drives the rest of the other activities -- Architecture-driven at its finest! The process as described in this course develops a design model, not a separate analysis model. To maintain a separate analysis model, some modifications to the process would be necessary, the discussion of which is out of the scope of this course. Emphasize the Use-Case Analysis activity and how it describes a process for finding classes and objects from use cases. Some people have called it: 'closing the traceability gap’ -- use cases and scenario's help you get from requirements to objects. (Analysis Modeling) (Interaction Diagrams And Class Diagrams) Use Case Realizations  Remember, we start off with the Use Case Model and supplementary info (Glossary; Domain model; business model…) from Requirements Workflow and ultimately end up with a Design Model – an abstraction of the source code. Design activities center around architecture – the main focus of early design iterations. We here, however, will concentrate on the activities of the Designer. Module 5 - Analysis and Design Overview

Read and study remaining slides on your own Read and study remaining slides on your own. (This does not mean ignore them, please…)

The Architect (very briefly) Establishes the overall structure for each architectural view: the decomposition of the view, the grouping of elements, and the interfaces between these major groupings. In contrast with the other workers, the Architect's view is one of breadth, as opposed to depth

The Designer (briefly) Defines the responsibilities, operations, attributes, and relationships of one or several classes and determines how they should be adjusted (modified, refined, morphed into other design / implementation artifacts (like packages, subsystems, etc.)) to support the implementation environment. Is usually responsible for Use-Case Realizations, in order to ensure the overall consistency of how a particular use case is realized using design elements.

The Database Designer (briefly) Defines the tables, indexes, views, constraints, triggers, stored procedures, table spaces or storage parameters, and other database-specific constructs needed to store, retrieve, and delete persistent objects. This information is maintained in the Data Model.

Reviewers Architecture Reviewer plans and conducts the formal reviews of the software architecture in general. The Design reviewer plans and conducts the formal reviews of the design model.

Workers and Their Responsibilities OOADv4.2 Instructor Notes Workers and Their Responsibilities Architect Architect: Establishes overall structure of each of the views. Decomposition; Breadth Designer Use-Case Realization Again, the focus of this course is on the activities and artifacts of the Designer. Design Model Package/ Subsystem Software Architecture Document Class Design Reviewer DB Designer: Designs tables, stored procs Indexes, etc. needed to store, maintain persistent data Data Model Database Designer Architecture Reviewer Designer: Responsible for the operations, attributes, and relationships of one or several classes and how they are implemented; Design packages; UC Realizations Module 5 - Analysis and Design Overview

Review: Analysis and Design Overview OOADv4.2 Instructor Notes Review: Analysis and Design Overview What is the purpose of Analysis and Design? What are the input and output artifacts? Name and briefly describe the 4+1 Views of Architecture. What is the difference between Analysis and Design? What is the purpose of Architectural Analysis? What is the purpose of Use-Case Analysis? What are the major responsibilities of the Architect, Developer, Database workers? Module 5 - Analysis and Design Overview