4. What is Software
▪ Instruction – executed provide
desire features, function &
performance.
▪ Data structure – to adequately
manipulate operation.
▪ Documents – operation and use of
the program.
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5. Hardware Vs Software
Hardware Software
Manufactured
Developed/
engineered
wear out
deteriorate
Built using
components
Custom built
Relatively
simple
Complex
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12. Software Myths
▪ Beliefs about software and the
process used to build it.
▪ Myths have number of attributes
that have made them insidious
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13. Management Myths
Myth1:
We already have a book that's full of
standards and procedures for building
software, won't that provide my people
with everything they need to know?
Reality :
▪ Are software practitioners aware of
existing standards?
▪ Does it reflect modern software
engineering practice?
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14. Customer Myths
Myth1:
A general statement of objectives is sufficient
to begin writing programs— we can fill in the
details later.
Reality :
▪ A poor up-front definition is the major cause
of failed software efforts.
▪A formal and detailed description of the
information domain, function, behavior,
performance, interfaces, design constraints,
and validation criteria is essential.
▪These characteristics can be determined only
after thorough communication between
customer and developer.
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15. Practitioner’s Myths
Myth1:
Once we write the program and get it to
work, our job is done.
Reality :
▪ Someone once said that "the sooner
you begin 'writing code', the longer it'll
take you to get done."
▪ Industry data indicate that between 60
and 80 percent of all effort expended
on software will be expended after it is
delivered to the customer for the first
time.
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18. s/w engineering
▪ Technological and managerial discipline
▪ Systematic production and maintenance of software products
▪ Developed and modified on time and within cost estimates
20. Total effort devoted to s/w
▪ Of the total 100 %:
▪ 90 % for s/w development (out of this about 60 % for s/w
maintenance)
▪ 10 % for h/w
21. Distribution of effort
▪ s/w development – 40%
o Analyze and design – 16%
o Implement - 8%
o Test – 16%
▪ Maintenance – 60%
o Adapt – 12%
o Enhance – 36%
o Fix – 12%
23. Programmer’s time
▪ Writing programs – 13%
▪ Reading programs and manuals – 16%
▪ Job communication – 32%
▪ Personal – 13%
▪ Misc – 15%
▪ Training – 6%
▪ Mail – 5%
24. Quality and productivity factors
▪ Individual ability
▪ Team communication (BROOKS LAW)
▪ Product complexity
▪ Appropriate notations
▪ Systematic approaches
▪ Change control
▪ Level of technology
▪ Level of reliability
▪ Problem understanding
▪ Available time/ calendar time
▪ Required skills
▪ Facilities and resources
▪ Adequacy of training
▪ Management skills
▪ Appropriate goals
▪ Rising expectations
▪ Other factors
26. What is SE ?
The application of systematic,
disciplined,
quantifiable approach to the
development,
operation and
maintenance of software;
that is, the application of engineering to software.
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27. Software Engineering – Layered Technology
Layered Technology
A quality focus: the “bedrock”
Process model: the “framework”
Methods: technical “how to’s”
Tools: CASE preferred
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30. Software Product
Dr. V. Sakthivel & Dr.K.P.Vijayakumar AP(Sr.G) /SCOPE,
VIT –Chennai Campus
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31. Complex System
▪ Complex System
▪ Air traffic control system
▪ Police command and control system
Source : Google
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32. System vs Software Engineering
▪ Software engineering is part of the
system engineering
▪ Entails in software development
▪ Related to all the perspective of
computer based system
development which consists of
Hardware, Software and Process
Engineering
▪ entails in system specification,
architectural design, integration
and deployment
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