Note for UML and Design Pattern - UDP By sudha rohini

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RT41052 UML & DESIGN PATTERNS Course Objectives: The focus of this course is on design rather than implementation. 1. Introducing the Unified Process and showing how UML can be used within the process. 2. Presenting a comparison of the major UML tools for industrial-strength development. 3. introduction to design patterns, practical experience with a selection of central patterns. Unit I Introduction Introduction to OOAD; typical activities / workflows / disciplines in OOAD, Introduction to iterative development and the Unified Process, Introduction to UML; mapping disciplines to UML artifacts,Introduction to Design Patterns - goals of a good design, Introducing a case study & MVC architecture 1.1 Introduction to OOAD Object-Oriented Analysis and Design: In object-oriented analysis, there is an emphasis on finding and describing the objects or its concepts in the problem domain. For example, in the case of the flight information system, some of the concepts includes Plane, Flight, and Pilot. In object-oriented design, there is an emphasis on defining software objects and how they collaborate with each other to fulfill the requirements. The combination of these two concepts shortly known as object oriented analysis and design. 1.1.1 Typical activities / workflows / disciplines in OOAD 1

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Activity Roles have activities that define the work they perform. An activity is something that a role does that provides a meaningful result in the context of the project. An activity is a unit of work that an individual playing the described role might be asked to perform. The activity has a very clear purpose, normally expressed in terms of creating or updating some artifacts,like a model, a class, a plan. Each and every activity is assigned for a specific role. The granularity of an activity is basically a few hours to a few days, it generally involves one role, and affects one or only a small number of the artifacts. An activity must be used as an element of planning and progress.If it is too small, then it will be neglected, and if it is too large, then the progress would have to be expressed in terms of an activity’s parts. Activities should be repeated number of times on same artifact, especially when going from one of the iteration to another, refining and expanding the system, by means of the same role, but not necessarily of the same individual. Steps Activities are broken down into several steps. Steps fall into the three main categories: 2

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• Thinking steps: is a step where the individual performing the role understands the nature of task,gathers and then examines the input artifacts, and formulates the outcome. • Performing steps: is a step where the individual performing the role creates or updates certain artifacts. • Reviewing steps: is a step where the individual performing the role inspects the results against some criteria. It is not necessary to perform these steps each time an activity is invoked, and so they can even be expressed in the form of alternate flows. Example of steps: The Activity: Find use cases and actors decomposes into the following steps: Step1. Find actors Step2. Find use cases Step3. Describe how actors and use cases interact Step4. Package use-cases and actors Step5. Present the use-case model in use-case diagrams Step6. Develop a survey of the use-case model Step7. Evaluate your results. The finding part [steps 1 to 3] needs some thinking.The performing part [steps 4 to 6] involves capturing the result in use-case model; the reviewing part [step 7] is the one where the individual performing the role evaluates the result to assess the completeness, robustness, intelligibility, or other qualities. Work Guideline Activities can have associated Work Guidelines, that present techniques and practical advice which is useful to the role performing the activity. 3

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Workflow A mere enumeration of all the roles, activities and artifacts do not constitute a process.we require a way to describe meaningful sequences of activities which produce some valuable result, and also to show interactions between the roles. A workflow is a sequence of activities that produces a result of observable value. In UML terms, a workflow may be expressed as a sequence diagram, a collaboration diagram, or even as an activity diagram. We use a form of activity diagrams in the RUP. For each and every discipline, an activity diagram is presented. This diagram shows the workflow, that is expressed in terms of the workflow details.The great difficulties of describing the process is that there are number of ways in order to organize the set of activities into the workflows. RUP is organized using the following: • Disciplines • Workflow details Workflow Detail For most of the disciplines, you may also find the workflow detail diagrams,that shows the group of activities which are often performed "together". 4