1. SOFTWARE ARCHITECTURE AND DESIGN
TAYYABA SANA
Lecture#1

2. Learning Goals
Learn key concepts of software design and architecture .
Experiencing the software design and architecture design process.
Providing insight in best practices and difficulties in software architecture design.

3. Learning outcomes Rationale for software design
Software analysis and design methods
Software design models
Design principles
OO design
Design patterns

4. Learning Outcomes Rationale for software architecture
Modeling Software architecture(ADLs).
Software architectural views
Software architectural documentation
Software architecture design method
Synthesizing Software architecture
Software architecture patterns
Evaluation of software architecture

5. Learning outcomes
Modeling method
Pattern
Evaluation

6. Project(2-3 member group)
Method  Deliverables
Select Problem domain Proposal
Problem analysis and domain analysis  RS and FS
Architectural view modeling  Architectural design
Software design models Detailed design
Applying architectural /design patterns  improved design
Evaluating software architectures  presentation

7. Rationale for software architecture
Marcus Vitruvius polio
Author of De Architectura(ten books of architecture)
Structure must exhibit three properties
strong
Usable
beautiful

8. Tools Building a large palace vs building a large software
Does any comparison exist?

9. To build a palace you need
Architectural Design
Architecture realization
Building
Architecture

10. To build a software System
Data structures
Programmers
But can not build without design because of
Large Systems(Distributed)
Many people work on same problem
Complex
Millions of lines of codes
Budget and time issues etc.

11. To build a Software you need
Architectural Design
Architecture realization
Building
Architecture

12. SDLC Requirement phase Analysis Design Implementation Testing
Where is Architecture?

13. SDLC Requirement phase  what customer Wants?
Architecture Design High level design
Analysis What is domain?
Design  How? (detailed)
Implementation  Do
Testing  Test
Where is Architecture?

14. Rationale for software Architecture
Abstraction specification
Stakeholders communication
Coping with evolution
Guides software development process
Organization of the development project
Large scale reuse

15. Abstraction specifications
Abstraction means to View only relevant information
Architecture represents high level abstract specification
helps to cope with complexity
Improves understanding of software system
Examples?

16. Stakeholders Communication
Stake holders of a system
End users
Managers
Programmers
Architects
etc.
Architecture is common medium of communication between different stake holders
Improves understanding of system between different stakeholders

17. Coping with evolution Helps dealing with changes and evolution
Changes will be limited to abstraction boundaries
Balanced between fixed and adaptable parts of the system

18. Guide for software development process
Architecture is explicit
Focuses on architectural components
Analyze and design based on architectural components

19. Organization of the development project
The architecture influences the organizational structure for development/maintenance efforts
Examples include
Team divisions
Budgeting, planning
Work breakdown structures
Documentation organization
Basis for integration, testing, deployment, maintenance

20. Large scale reuse Software architecture is abstract specification
Represents set of systems
Can be reused for systems exhibiting similar structure and requirements
Can produce software product lines

21. Dicussions? Architecture is just paper Architecture Vs. Design
Architecture Vs. infrastructure
Architecture Vs. Technology
Architecture Vs. Structure
Architecture -View
Architecture Vs. Art

22. Architecture is just paper…
Every System has Architecture ,either Visible or not
Architecture eventually resides in executable code
A systems' architecture may be visualized in models, which can be executable

23. Architecture Vs. Design
All architecture is design but not vise versa
Design
Detailed Design
High level design

24. Architecture vs infrastructure
Infrastructure is important part of architecture
Infrastructure could be a view on architecture
Architecture is more than infrastructure

25. Architecture Vs. Technology
Architecture is more than list of products
Architecture implementation is shaped by technology
Architecture is not directly bound to technology

26. Architecture Vs. Structure
Architecture includes structure but not every structure is architecture
Architecture is abstraction of underlying structure
Architecture is more than structures.

27. Architecture-views Architectural is flat only in trivial systems
Multiple stakeholder multiple concerns Multiple architectural views
Complex systems usually have more than one architectural views

28. Architecture Vs. Art Complexity is maximum in today’s systems
Creative part is minimal in these systems
Architecture design is explicit rational activity

29. Software Architecture
In Software Architecture in Practice (2nd edition), Bass, Clements, and Kazman define architecture as follows:
“The software architecture of a program or computing system is the structure or structures of the system, which comprise software elements, the externally visible properties of those elements, and the relationships among them. Architecture is concerned with the public side of interfaces; private details of elements—details having to do solely with internal implementation—are not architectural.”