UNIT - 3
SOFTWARE DESIGN
•Design process
•Design Concepts
•Design Model
•Design Heuristic
•Architectural Design
•Architectural styles
•Architectural Mapping using Data Flow
•User Interface Design:
•Interface analysis,
•Interface Design
•Component level Design:
•Designing Class based components,
•traditional Components.
Design process
3 Characteristics
•Implement all the explicit and implicit requirements
•Must be a readable
•Provide complete picture of a software
Guidelines
•Should Be Modular
•Should Contain Distinct Representations Of Data
•Should Lead To Data Structures
•Should Lead To Components
•Should Lead To Interfaces
•Should Be Derived Using A Repeatable Method
•Should Be Represented using a notation
Quality Attributes
•Usability
•Reliability
•Performance
•Supportability
•Maintainability
Design
process
Design Concepts
Framework for implementing the right software
Following are certain issues that are considered while designing the
software:
•Abstraction
•Software Architecture
Structural Models
Framework Models
Dynamic Models
Process Models
Functional Models
•Patterns
•Separation
•Modularity
Design classes
•Different Types Of Design Classes
•User Interface Classes
•Business Domain Classes
•Process Classes
•Persistent Classes
•System Classes
Purpose of Design
Design
Heuristics
ARCHITECTURAL STYLES AND DESIGN
•Architectural Model Or Style Is A Pattern
•Computer-based Systems
•Set Of Connectors
•Semantic Models
Number Of Fundamental Ways:
•Scope Of A Pattern Is Less Broad
•Pattern Imposes A Rule On The Architecture
Data-centered architectures
Data-flow architectures
Main program/subprogram architectures
Layered architectures
Representing the System in
Context
Defining
Archetypes
Design Analysis Activities
•Collect scenarios
•Elicit requirements, constraints, and environment
description
How the architectural styles/patterns chosen to
address the scenarios and requirements.
•Evaluate
•Identify
Step 1:Review the fundamental system model
Context-level DFD for the Safe Home security function
Step 2. Review and refine data flow diagrams for the software.
Level 1 DFD for the Safe Home security function Level 1 DFD for the
Safe Home security
Step 3. Determine whether the DFD has transform or
transaction flow characteristics.
Level 2 DFD that refines the monitor sensors transform
Step 4. Isolate the transform center by specifying
incoming and outgoing flow boundaries
Step 5. Perform “first-level factoring.”
Step 6. Perform “second-level factoring.”
Step 7. Refine the first-iteration architecture
using design heuristics for improved software
quality.
Summary Of Previous Class
Architectural styles and design
• Data-centered architectures
• Data-flow architectures
• Main program/subprogram architectures
• Layered architectures
Architectural Mapping using Data Flow
• 7 Steps for mapping using data flow
Quiz for Previous class topics using kahoot:
ARCHITECTURAL STYLES AND PATTERNS KAHOOT.IN
LINK IN CHATBOX PIN: 08663629
User Interface Design
3 Golden Rules
• Place the User in Control
• Reduce the user’s memory load
• Make the interface consistent
User and Tasks Analysis
• It’s a form of field research
Analyzed by following points
User needs
System fits
Confidence
Styles
Some Protocols for obtaining proper UID
• Prototyping
• Usability Inspection
• User testing
• Graphical user interface design
Summary Of Yesterday’s Class
• 3 Golden Rules
• User and Tasks Analysis
• Some Protocols for obtaining proper UID
User Interface Design - Quiz
• testmoz.com/5278166
• 15 Questions MCQ (8 mins)
Interface Analysis , Interface Design
• Focus on user’s experience and interactions
• Supports – usability, interactions, visual demand
• Unique skills and knowledge
User Interface Design Activities
• Interface Analysis and modeling
• Interface Design
• Interface Construction
• Interface Validation
User Analysis
• User Interviews
• Sales Input
• Marketing Input
• Support Input
Summary Of Yesterday’s Class
Interface Analysis , Interface Design
User Interface Design Activities
User Analysis
Component Based Designing
To Check Whether Certain Functions To Work Or Not
Coupling
Five Levels Of Coupling
• Content Coupling
• Common Coupling
• Control Coupling
• Stamp Coupling
• Data Coupling
Design Verification
Cohesion
Various types of cohesion are listed in the diagram
Assignment – 3
Designing Class based
components and traditional
Components.
ITS TIME FOR MCQs!!!!
End of Unit – 3!!!
