Low Level Design

Index:

1. Introduction & Representation techniques
   1. OOAD (Object Oriented Analysis and Design) – CDAC reference
      1. Representation using UML(Unified Modelling Language) notation
      2. For Drawing UML Tools-
         • Offline- StarUML,
         • Online – Diagrams.net
      3. OO Analysis and Design Methodolgy
      4. OO Notation
      5. OO tool to draw OOAD Design
2. OOP (implementation)
   1. OOP Principal
      1. P.I.E.A.
   2. SOLID
   3. Association, Aggregation, Composition
3. Design pattern (implementation)
   • Behavioural
   • Creational
   • Structural
4. Interview Outline

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What does a OO Designer needs?

1. OO Concepts
2. OO Language
3. OO Analysis and Design Methodolgy
4. OO Notation
5. OO tool to draw OOAD Design

OOAD Techniques

1. Fusion
2. Jacobson
3. Rumbaugh
4. Booch
5. Rational Unified Process (RUP) with Unified Modeling Language (UML)

OO Design Tools

1. Rational Software
2. StarUML

UML Diagrams for OOAD design using RUP

At core we have Models and using which various representation can be drawn for specific analysis-

1. Use-case Diagrams
2. Class Diagrams
3. Object Diagrams
4. State-chart Diagrams
5. Sequence Diagrams

Use Case Analysis – Drawing the Use Case Diagram

My take- useful in case of establishing relation between use-case/functionality

• Stick Figure Represents Actor
• Oval Represents Use Case
• The Rectangle represents System Boundary

Use Case Analysis – Use Case Relationships

3 kinds of relationships between use cases

1. Include
2. Extend
3. Uses

Include:

1. «include» stereotype indicates that one use case “includes” the contents of another use case.
2. Enables factoring out frequent common behavior

Use case “A” includes use case “B” if :

1. B describes scenario which is part of scenario of A &
2. B describes scenario common for a set of use cases including A

Extends:

1. «extend» stereotype indicates that one use case is “extended” by another use case.
2. Enables factoring out infrequent behavior or error conditions
3. Used to show optional behaviour for a use case which will be required only under certain conditions

Uses:

1. «uses» stereotype indicates that one use case is precondition for executing another use case
2. Use case “A” uses use case “B” if
   1. B describes a scenario which is not part of scenarios carrying out service A &
   2. B is a precondition for successful invocation of A

Examples

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OOAD: Activity Diagram

Depicts business processes and data flows to model the complex logic within the system

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OOAD: Sequence Diagrams

Models the time ordering of messages between classifiers to accomplish given
functionality

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UML Diagrams: Collaboration Diagrams

Focuses on the structural organisation of objects that send and receive messages.
Known as communication diagrams in UML 2.0.

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UML Diagrams: Class Diagrams

Models a collection of static model elements such as classes, their contents and
relationships

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UML Diagrams: State machine Diagrams

Describes states of an object and transitions between the states

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UML Diagrams: Component Diagrams

Depicts the components, their interfaces and interrelationships

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UML Diagrams: Deployment Diagrams

Shows the execution architecture of the application