introduction to the software architecture

8/6/2019 Introduction to the Software Architecture

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Software Design and Architecture

Muhammad Nasir

Introduction to Software Architecture

[email protected]


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Agenda Challenges in Software Engineering

How Software Architectures can Help

What is Software Architecture?

Why Develop a Software Architecture?

Software Architecture is Abstraction

Factors Influence Architecture

Software Architecture Design Methods

Challenges when Creating a Software Architecture Design and Architecture Difference


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Goal (s) of this lecture To give you an understanding of the concept

Software Architectures, and its importance in

software development. To make you understand the challenges of

Software Architectures.


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Challenges in Software Engineering

Reduce Development Cost

Delivery on time and within budget

Increase System Quality

Decrease Maintenance Costs

80% of a systems lifespan is spent in

maintenance phase. Reduce Time-To-Market

Manage increasing Complexity


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How Software Architectures can

Help

Understanding System

Theoretical Limitations

Planning Resources

Labor

Communication

Customer Stakeholders

Evaluating Quality

Identifying Opportunities for Reuse


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What is Software Architecture?

The software architecture of a program or

computing system is the structure or

structures of the system, which comprisesoftware elements, the externally visible

properties of those elements, and the

relationships among them. (Bass, Clements, Kazman)

For more (much more),

http://www.sei.cmu.edu/architecture/definitions.html


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Software Architecture is Abstraction


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Software Architecture in Development?


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Why Develop a Software Architecture?

Why spend time on developing a Software

Architecture?

We have the requirements It takes time

We want to start coding

Ostrich Algorithm


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Why Develop a Software Architecture!

Early Problem Analysis

Communicate back to Customer

Define Interfaces Avoid Problems during Integration

Early Information for

Testing

Planning


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Challenges with Software Architectures

Requirements alone do notgenerate aspecific Software Architecture?

There are other factors. Which? Who has input to the Software Architecture?

Who are users of the Software Architecture?

What are the ramifications of a Software

Architecture?


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Influencing Factors Technical & Organizational Factors

Development Organization

Previous Experiences

Quality Requirements from Target Domain

Technical Environment

Business Factors Overall Business Goals

System Stakeholders Management Low cost, keep people employed

Marketing Neat features, low cost, time-to-market

End UserBehavior, performance, reliable Maintenance org. Modifiable, understandable

Customer Low cost, timely delivery

Other Quality Requirements


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Factors Influence Architecture

ArchitectureInfluence Factors

A Software Architecture Manifest Early Design Decisions

Constrains an Implementation

Dictates Organizational Structure

Impacts Change Management

Facilitates Evolutionary Prototyping

A Developed Software System Adds to previous experiences

May affect business goals

Refines development organization(Process Improvement)

Affect customer requirements

May revolutionize Computer Industry (e.g.GUI)


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Software Architecture DesignM

ethods

Not one method!

Multiple approaches, depending on the

system that is built. Different methods in different companies.

Different attitudes towards SA: Formal

Semi-formal Agile

etc.


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How to Develop a Software Architecture

A Software Architecture sets the theoreticalmax & min boundaries of Quality Attributes

for a Software System E.g. Performance, Modifiability, Reliability

Hence, Requirements on Quality Attributesshould drive Software Architecture Design.

Structured Software Architecture DesignMethods Bosch

Hofmeister et al.


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Challenges when Creating a

Software Architecture

To model an architecture that meets therequirements. Trade-offs between conflicting requirements.

That can adapt to changed requirements.

To document the architecture models in the rightway. Everyone should understand!

To maintain/manage the architecture.

To spread knowledge about the architecture In the project

Outside the project


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Design and Architecture Difference

No clear boundary line.

All architecture is design all design is

notarchitecture!

Architecture building blocks:

Components, modules

Design building blocks:

Classes/objects


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The End

Thanks for listening

Questions would be appreciated.

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