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Software Engineering Methodologies Slide 1

Software Engineering

Methodologies (Introduction)

By

Shahbaz Pervez Chattha

[email protected]

web-page:

http://web.uettaxila.edu.pk/CMS/coeSEMms/index.asp
http://web.uettaxila.edu.pk/CMS/coeSEMms/index.asphttp://web.uettaxila.edu.pk/CMS/coeSEMms/index.asp


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Course titleSoftware Engineering Methodologies

Course code

Instructor: Shahbaz Pervez Chattha Semester2008

VenueClass room: 1

Credit hours: 3

Instructors Office NumberDirect: 051-9047465

Visiting hoursBy availability

Instructors [email protected]

Mode of lecture delivery:Multimedia

Course TA/: Mr. Farhan Adil ScheduleFridays 3:006:00 pm

Software Engineering Methodologies
mailto:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]


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Why Software Engineering?

Software development is hard !

Important to distinguish easy systems(onedeveloper, one user, experimental use only) fromhard systems (multiple developers, multiple users,

products)

Experience with easy systems is misleading

One person techniques do not scale up

Analogy with bridge building:

Over a stream = easy, one person job

Over River Jhelum ? (the techniques do not scale)


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Why Software Engineering ?

The problem is complexity

Many sources, but sizeis key:

UNIX contains 4 million lines of codeWindows 2000 contains 108 lines of code

Software engineering is about managingthis complexity.


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Recommended Course Textbooks

Sommerville I. (2001)

Software Engineer ing

6th Edition, Addison-Wesley, Harlow,Essex, UK

Roger S. Pressman (2000)

Software Engineering:A Practitioner's Approach,

5th edition, McGraw-Hill, USA
http://www.amazon.com/exec/obidos/ASIN/0073655783/dataprocesorg-20


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Recommended Course Textbooks

Project Management

A systems Approach to Planning, Scheduling and

Controlling.(7th

Edition)By Harold Kerzner


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Outline Syllabus

1. Introduction to Software Engineering2. Software Processes & Process Improvement

3. Software Design and Implementation

4. Software verification, validation and testing

5. Quality Assurance

6. Configuration Management

7. Metrics and measurement8. Requirements Engineering

9. Software Project Management

10. Risk Management

11. WBS Estimation & Scheduling

12. MS Project, ToolsApplications

13. Reengineering

14. Integration & Testing15. Real Time and Embedded Systems Design

16. Software Engineering in Pakistan Industry


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What is software?

Computer programs and associated documentation

Software products may be developed for a particularcustomer or may be developed for a general market

Software products may be

Generic - developed to be sold to a range of differentcustomers

Bespoke (custom) - developed for a single customeraccording to their specification


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What is software engineering?

Software engineering is an engineering discipline

which is concerned with all aspects of software

production

Software engineers should

adopt a systematic and organised approach to their work

use appropriate tools and techniques depending on

the problem to be solved, the development constraints and

the resources available


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What is the difference between software

engineering and computer science?

Computer Science Software Engineering

is concerned with

Computer science theoriesare currentlyinsufficient to act as a complete underpinning

for software engineering

theory

fundamentals

the practicalities of

developing

delivering useful software


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What is the difference between software

engineering and system engineering?

System engineering is concerned with all aspectsof computer-based systems development includinghardware, software andprocess engineering

Software engineering is part of this process

System engineers are involved in

systemspecification, architectural design,integration and deployment


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What is a software process?

A set of activities whose goal is thedevelopment or evolution of software

Generic activities in all software processes are:

Specification - what the system should do and itsdevelopment constraints

Development -production of the software system

Validation - checking that the software is what thecustomer wants

Evolution - changing the software in response tochanging demands


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What is a software process model?

A simplified representation of a software process,presented from a specific perspective

Examples of process perspectives:

Workflow perspective represents inputs, outputs and dependencies

Data-flow perspective represents data transformation activities

Role/action perspective represents the roles/activities of thepeople involved in software process

Generic process models

Waterfall Evolutionary development

Formal transformation

Integration from reusable components


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What are the costs of software

engineering?

Roughly 60% of costs are development costs,

40% are testing costs. For custom software, evolution

costs often exceed development costs

Costs vary depending on the type of system being

developed and the requirements of system attributes

such as performance and system reliability

Distribution of costs depends on the development

model that is used


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What are software engineering

methods?

Model descriptions (Descriptions of graphical

models which should be produced)

Rules (Constraints applied to system models)

Recommendations(Advice on good design practice)

Process guidance (What activities to follow)

Structured approaches to software development

which include system models, notations, rules, design

advice andprocess guidance


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What is CASE ?

(Computer-Aided Software Engineering)

Upper-CASE

Tools to support the early processactivities of requirements and design

Lower-CASETools to support later activities such as

programming, debugging and testing

Software systems which are intended to provideautomated support for software process activities, suchas requirements analysis, system modelling, debuggingand testing


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What are the attributes of good

software?

Maintainability Software must evolve to meet changing needs

Dependability

Software must be trustworthy

Efficiency Software should not make wasteful use of system resources

Usability

Software must be usable by the users for which it was designed

The software should deliver the required functionality

and performance to the user and should be

maintainable, dependable and usable


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What are the key challenges

facing software engineering?

Software engineering in the 21st century faces

three key challenges:

Legacy systems

Old, valuable systems must be maintained and updated

Heterogeneity

Systems are distributed and include

a mix of hardware and software

Delivery There is increasing pressure

for faster delivery of software


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Professional and ethical

responsibility

Software engineering involves wider responsibilitiesthan simply the application of technical skills

Software engineers must behave in an honest andethically responsible way if they are to be respectedas professionals

Ethical behaviour is more thansimply upholding the law


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Software Processes

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