1.Evolving Role of
software.
• Software has become part of the national
infrastructure
• Software is the differentiating factor
• Hardware is general-purpose, software is applicationspecific
• Hardware is becoming a commodity
• Software is often costlier than the hardware it runs
on.
2. Define Computer
Software.
• A Computer Software is a sequence of instructions
written to perform a specified task with a computer.
• A computer requires programs to function, typically
executing the program's instructions in a central
processor.
• The program has an executable form that the computer
can use directly to execute the instructions. The same
program in its human-readable source code form, from
which executable programs are derived enables a
programmer to study and develop its algorithms.
3 .What are the
characteristics of software
? Discuss any three of them
‰ Software is developed, it is not manufactured in the
classical sense.
‰ Software doesn’t “wear out”.
‰ Although the industry is moving toward componentbased construction, most software continues to be
custom built.
4 .Write down the
characteristics of h/w or s/w on
failure cure ?
•
•
•
•
Larger problems,
Lack of adequate training in software engineering,
Increasing skill shortage,
Low productivity improvements.
SYSTEM SOFTWARE
¾ COLLECTION OF PROFRAMS WRITTEN TO SERVICE OTHER PROGAMS
¾ HEAVY INTERACTION WITH COMPUTER HARDWARE
¾ CONTAINS COMPLEX DATA STRUCTURES AND MULTIPLE EXTERNAL
INTERFACES
¾ CONCURRENT OPERATION THAT REQUIRES SHEDULING
EXAMPLE:
COMPILERS , EDITORS
FILE MANAGEMENT UTILITIES
OTHER SYSTEM APPLICATIONS
DRIVERS AND NETWORKING SOFTWARE
APPLICATION SOFTWARE
y CONSISTS OF STANDALONE PROGRAMS
y USED TO SOLVE SPECIFIC BUSINESS NEEDS
y PROCESS TECHNICAL DATA/TECHNICAL
DECISIONS
y CONTROL BUSINESS FUNCTIONS IN REAL TIME
y EXAMPLE:
y CONVENTIONAL DATA PROCESSING APPLICATIONS
y REALTIME MANUFACTURING PROCESS CONTROL
ENGINEERING & SCIENTIFIC S/W
y CHARACTERISED BY CONVENTIONAL NUMERICAL ALGORITHMS
y INTERACTIVE APPLICATIONS TO TAKE ON REALTIME
y EXAMPLE:
• COMPUTER AIDED DESIGN(CAD/CAM)
• SYSTEM SIMULATION
• SPACE SHUTTLE ORBITAL DYNAMICS
• MOLECULAR BIOLIOGY TO AUTOMATED
MANUFACTURING
• USED IN EDUCATIONAL FIELD FOR CREATING
INTERACTIVE APPLICATIONS
NET SOURCING
y WWW – A COMPUTING ENGINE & CONTENT
PROVIDER
y CHALLENGE OF S/W ENGINEERS IS TO
ARCHITECT SIMPLE
y SOPHISTICATED APPLICATIONS THAT PROVIDE
BENEFIT TO TARGET AND END-USER MARKETS
WORLDWIDE
y EXAMPLE:
• PERSONAL FINANCIAL PLANNING
WEB APPLICATIONS
• SPAN A WIDE ARRAY OF APPLICATIONS
• SET OF LINKED HYPERTEXT FILES
• E-COMMERCE & B2B APPICATIONS GROW IN
IMPORTANCE
• PROVIDE STAND ALONE FEATURES,COMPUTING
FUNCTIONS & CONTENT TO END-USER
• INTEGRATED WITH CORPORATED DATABASES &
BUSINESS APPLICATIONS
PRODUCT LINE SOFTWARE
y PROVIDE SPECIFIC CAPABIITY FOR USE BY MANY DIFFERENT
CUSTOMERS
y FOCUS ON LIMITED & ESOTERIC MARKETPLACE
y EXAMPLE:
• WORD PROCESSING
• SPREADSHEETS
• COMPUTER GRAPHICS
• DATABASE MANAGEMENT
• MULTIMEDIA & ENTERTAINMENT
• BUSINESS FINANCIAL APPLICATIONS
EMBEDDED SOFTWARE
y RESIDES WITHIN A PRODUCT OR SYSTEM
y USED TO IMPLEMENT & CONTROL FEATURES
y PERFORM LIMITED & ESOTERIC FUNCTIONS
y PROVIDE SIGNIFICANT FUNCTION & CONTROL CAPABILITY
y EXAMPLE:
• KEYPAD CONTROL FOR A MICROWAVE
OVEN
UBIQUITUOUS COMPUTING
• RAPID GROWTH OF WIRELESS NETWORKING
LEADS TO DISTRIBUTED COMPUTING
• TO DEVELOP SYSTEMS & APPLICATION S/W THAT
WILL ALLOW SMALL DEVICES , PERSONAL
COMPUTERS & ENTERPRISE SYSTEM TO
COMMUNICATE ACROSS VAST NETWORKS
ARTIFICIAL INTELLIGENCE
y USE OF NON-NUMERICAL ALGORITHMS TO SOLVE COMPLEX
PROBLEMS
y NOT AMENABLE TO COMPUTATION / STRAIGHT FORWARD
ANALYSIS
y EXAMPLE:
• ROBOTICS
• EXPERT SYSTEMS
• PATTERN RECOGNITION(IMAGE AND VOICE)
• ARTIFICIAL NEURAL NETWORKS
• THOREM PROVING
• GAME PLAYING
A growing trend that result in
distribution
of source code for system
Challenges thrown by open system
applications like operating system.
The challenge for software engineers is
to build source code that is self descriptive ,
but ,more importantly, to develop technique
that will enable both customers and
developers to know what changes have been
made and how those changes manifest
themselves within the software.
Legacy Software
y Older programs often referred to as legacy
software.
y Legacy software systems were developed
decades ago and have been continually modified
to meet changes in business requirements and
computing platforms.
y Many legacy system remain supportive to core
business functions and are indispensable to the
business.
y Legacy software is characterized by longevity and
business criticality.
Changes are made to legacy software
y The software must be adapted to meet the needs
of new computing environments or technology.
y The software must be enhanced to implement
new business requirements
y The software must be extended to make it
interoperable with more modern systems or
databases.
y The software must be re‐architected to make it
viable within a network environment.
Categories of software myths
• Software Myths – beliefs about software and
the process used to build it can be traced to
the earliest day of computing.
• Myths have a number of attributes that have
made them insidious.
• Management myths
• Customer myths
• Practitioner’s myths
Management myths.
Managers with software responsibility, like managers in most disciplines , are often under pressure to maintain budgets, keep schedules from slipping and improve quality.
Customer myths
The customer believes myths about software because software managers and practitioners do little to correct misinformation.
Practitioner’s myths
Software practitioners have been fostered by over 50 years of programming culture. programming was viewed as an art form.