This ppt will give anyone an insight on the introduction to software engineering

1. Software Engineering
INTRODUCTION
R. Aswin Herbert Sathsih.,MCA.,MPhil,(PhD)

2. Software Crisis
• 1940’s - Software Development is not an independent process.
• Person developed - Executed, Tested, Debugged and Maintained.
• Instruction written in assembly language.
• Final product – Poor Quality.
• Time and Money spent on maintaining the software,

3. Contd…Software Crisis Examples
• Development teams exceeding the budget.
• Late delivery of software.
• Poor Quality.
• User requirements not completely supported by the software.
• Difficult maintenance.
• Unreliable software.

4. Why Software Engineering ?

7. What is a Software ?
• Software can be defined as a set of instruction
which when executed on a computer accepts the
inputs and after doing required computations,
produces the output or result as per users
requirements.
• It is also accompanied by user manual so as to
understand so as to understand the features and
working of the software.

8. Software consist of …
• Source code.
• Executables
• User Manuals
• Requirement Analysis and Design Documents
• Installation Manuals

9. Hardware vs Software

10. Hardware
F
a
i
l
u
r
e
R
a
t
e
Time
WEAR OUT

11. Contd… Hardware
• Bath tub Curve.
• Is manufactured/ Assembled.
• Wear out.

12. Software
F
a
i
l
u
r
e
R
a
t
e
Time
CONTINUE AT THE SAME

13. Contd… Software
• It is developed or engineered
• Multiple copies can be produced
• Flexible and easily accommodate the changes
• Retire than wear out

14. Examples of Failed Projects
• June 1996 – Anane 5 launcher exploded after 40
seconds of take off.( 4 km)
• Loss – 400 million
• Error – Overflow in the conversion from 64 bit
floating point number to 16 bit signed integer.

15. Contd… Examples
• 1980 – Sperry Corporations in US – automate
income tax forms hired Internal Revenue Service.
• Loss – 103 million ( Development cost ) + 90 million
• Error – Inefficient to handle the load
• Result – 40.2 million interest paid to customers

16. Contd… Examples
• Therac-25 Radiation Therapy and X-Ray Machine.
• Error -Malfunctioning of arrow keys which were
not programmed.
• Result – High dose of radiations was given to
patients whereas only low levels are required.
• Loss - Killed several patients –

17. Contd… Examples
• Ministry of Agriculture in UK undergone a loss of
12 million pound.
• Space shuttle Columbia was delayed by three years –
Millions of dollars loss.
• Software errors

21. Software Engineering …
• Strategy for producing quality product.
• Economic
• Reliable
• Efficient
Or
Systematic transformation of a problem into a working software
solutions.

22. Advantages of using Software Engineering
• Improved Quality.
• Improved requirement Specification.
• Improved cost and schedules estimates.
• Better use of automated tools and techniques.
• Less defects in final product.
• Better maintenance of delivered software.
• Well defined processes.
• Improved productivity.
• Improved reliability

23. Software Products
Software
Products
Generic
Product
Customized
Product

24. Generic Product
• For general purposes audience.
• COTS – Commercial Off-the-shelf software.
• Tough in designing and marketing
• Imagination about the end-user is required.
• Needs market survey and general customer demand
analysis.
• Risk is more
• Examples : Word processors, Drawing packages,
Project Management Tools, etc.

25. Customized Product
• Also known as bespoke product.
• Developed for specific organization/Customer.
• Includes customer’s preferences & expectations.
• Designed stage by stage .
• Expensive.
• Examples : Air traffic control systems, Core banking
solutions

26. Software Attributes
• Maintainability
• Dependability
• Efficiency
• Usability

27. Contd…
• Maintainability
• Debug
• Modify
• Flexible
• Testability
• Portability
• Reusability
• Inter-Operability

28. Contd…
• Dependability
• Correctness
• Reliability
• Integrity
• Security
• Safety

29. Contd…
• Efficiency
• Memory Requirements
• Processing time
• Memory Utilization

30. Contd…
• Usability
• Training
• User Familiarity
• Consistency
• User Guidance
• Example : Scientific Calculator

31. Software Engineering Challenges
• The Legacy Challenge
• The Heterogeneity Challenge
• The Delivery Challenge
• The Trust Challenge

32. THANK YOU