Software Design

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Software Design

• An Introduction to Object Oriented Analysis and
  Design Using the Unified Modelling Language

Bill Keller Spring 2006
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Lecture 1 Introduction

• Introduction
• What the course is about
• What the course is not about
• Aims and Outcomes
• Teaching and Assessment
• Design Case Study
• Design Task
• Recommended Reading

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What the course is about

• An introduction to object-oriented analysis and
  design
• The software development process
• Object-orientation
• Requirements analysis and modelling
• Software quality
• The Unified Modelling Language (UML)
• Use case diagrams
• Static structure and the class model
• Object collaboration and interaction
• Object state and behaviour
• Team-working
• Managing the process

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What the course isnt about

• To keep the course manageable, we wont cover
• Requirements capture
• Interface design and HCI Issues
• Deployment and maintenance
• Some UML dealt with only briefly or not at all
• Packages and components
• Deployment diagrams
• Object constraint language

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Course Aims
This course aims to provide first year students
with

• An introduction to fundamental concepts of
  object-oriented analysis and design of software
• practical experience of software modelling and
  design techniques
• experience of team-working
• an introduction to the Unified Modelling Language

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Learning Outcomes

• On successful completion of the course students
  should be able to
• Appreciate the problems inherent in the design of
  high-quality software
• Demonstrate the skills needed to model software
  components using basic elements of the UML
• Work effectively as a part of a software design
  team
• Document design decisions appropriately

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Why UML?

• UML is a visual modelling language which
• supports analysis and modelling at all stages
• is an emerging standard for software modelling
• Is process neutral i.e. is not tied to any one
  particular design process
• We will cover core aspects of UML, including
• Use-case diagrams,
• Class diagrams,
• Interaction diagrams collaboration/sequence
• Statechart and activity diagrams

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A Little History

• Late 1960s
• Emergence of OO programming languages
• Simula-67, Smalltalk (1970)
• 1970s
• Appearance of first OOAD methodologies
• 1980s and early 1990s
• Many competing general development methods and
  modelling languages (over 50)
• The methods wars

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Emergence of UML

• By the mid 1990s three key methods had become
  prominent
• Rumbaugh Object Modelling Technique
• Booch Booch 93 OO Analysis and Design
• Jacobson OO Software Engineering
• 1995 Rumbaugh, Booch and Jacobson join forces in
  Rational
• Develop the (Rational) Unified Process
• Develop the Unified Modelling Language (UML)

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UML is.

• A ready-to use visual modelling language
• A language, not just a notation
• For OO analysis and design of (software) systems
• UML diagrams provide for various views of systems
• Simple and expressive
• UML has core set of expressive concepts/notations
• Extensible
• allows specialization/addition of
  concepts/notations
• An emerging standard for modelling systems

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UML is not

• A visual programming language
• UML is for modelling/conceptualizing/visualizing
  systems, not for implementing them
• Not tied to a particular programming language
• A development process
• UML is process neutral
• Not tied to a particular process (e.g. Unified
  Process)
• A development tool
• A guarantee of success

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System, Design, Model, Diagram

• Important to be clear about terminology
• System program or collection of programs meeting
  user requirements end goal of the development
  process
• Design collection of decisions about how to
  build system end product of the design process
• Model abstract representation of system or
  design from a particular viewpoint a product of
  some stage of the design process
• Diagram visual representation of (part of) model
  

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Models and UML Diagrams

• Use case model describes the high level
  functionality of system from users point of view
• UML use case diagram UML activity diagram
• Static model describes the elements of system
  and their organization and relationships
• UML class diagram UML package diagram
• Dynamic model describes behaviour of system over
  time
• UML collaboration diagram UML sequence diagram
  UML statechart diagram

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UML CASE Tools

• Poseidon UML Standard Edition
• A professional UML Case tool provided on lab PCs
• Poseidon UML Community Edition
• A cut-down version of the above that is freely
  downloadable from http//www.gentleware.com/
• Rational Rose
• Can be run from Sun machines? In .login file add
  the line source /local/global/rational_logi
  n
• To run, at prompt do
  rose
• Eclipse Omondo plug-in
• Useful if you like Eclipse.

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UML Drawing Tools

• Some drawing tools incorporate UML diagrams
• e.g. dia http//dia-installer.sourceforge.net/
• But for small design tasks, any half-way decent
  drawing package will probably do
• All the UML drawing in these lectures were
  produced with Windows AutoShapes
• Or you could just use paper and pencil
• Remember the goal is good design rather than
  pretty pictures!

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Teaching Sessions Lectures

• Generally there will be two lectures each week
• Tuesday 10.00 --11.00 in JMS Building 1A01
• Wednesday 9.00 -- 10.00 in JMS Building 1A01

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Syllabus

• What is Software Development and why is it hard?
• The Software Development lifecycle
• Object Orientation and Software Design
• Requirements Specification
• Requirements analysis and Use Cases
• Class Models and the UML Class Diagram
• Modelling Object Collaborations and Interactions
• Object Behaviour and the UML Stateflow Diagrams
• Software Quality

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Teaching SessionsDesign Workshops

• There will be a design workshop each week
• work together in small teams
• focus on a single design task
• Based around structured design exercises
• work through the development process
• hands-on experience of design techniques
• develop understanding of lecture material

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Formal Assessment

• Assessment for the course
• is based entirely on coursework
• focuses on a single software design task
• Assessed work will consist of
• two submissions of design documentation
• an oral presentation
• Assessed work will be team-based
• You will work together in teams in the design
  workshops and to complete the assessment

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Design TaskOnline Bookshop
Statement of Purpose The eVersity online bookshop
allows students and staff to purchase course
books quickly and easily. A user is able to
browse the book catalogue or search for
individual items by title or author. Required
books may be added to a purchase order. Payment
is by debit card although college staff can also
pay by salary deduction. College tutors can order
in textbooks for courses that they teach.
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Why Teamwork?

• Software design is usually a team effort
• Real-world software systems too large and complex
  to be tackled by a single individual
• good design requires various sorts of expertise
• Successful design projects need
• planning,
• communication
• management
• Teamwork plays a central role in this course

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Some Useful Texts

• Priestly, M (2003) Practical Object-Orientated
  Design with UML, (3rd Edition) McGraw-Hill
• Lunn, K. (2003) Software Development with UML,
  Palgrave
• Bennet, S, McRobb, S, and R Farmer (2002)
  Object-Oriented Systems Analysis and Design,
  McGraw-Hill
• Bennet, S, Skelton, J and K Lunn (2001) UML,
  Schaums Outlines series, McGraw-Hill
• Budgen, D (1994) Software Design, Addison-Wesley

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Other Resources

• The course web site
• Course outline information
• Lecture notes
• Seminar notes
• Details of design task and exercises
• Etc. etc.
• Look under
• Informatics home gt teaching gt course directory

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Summary

• The course covers key ideas in
• object oriented analysis and design
• UML
• Teaching is provided by a combination of
• lectures
• hands-on design workshops
• Assessment is entirely by coursework
• Based on a single design task
• Students work together in design teams

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Software Design