Transcript Information System Development and Programming Languages

Information system development
and
programming language
1
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Information system development
System is a set of components that interact to
achieve a common goal.
Information system (IS) is a collection of HW ,
SW, data, people and procedures that work
together to produce quality information.
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Information system development
System development cycle is a set of activities
used to build an information system.
System development cycle often organize
activities by grouping them into larger categories
called phases.
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Most system development cycles contain 5 phases
Planning
Operation, Support
and Security
Perform
maintenance
•Review
Project
requests
Perform detailed
analysis
•Develop
•Acquire
HWprograms.
andrequest
SW, if
•Prioritize
project
activities
activities
•Conduct preliminary
•Allocate
resources
•Install
and
test new
necessary
•Monitor
system
•Study
current
system
investigation
Analysis
•Form project
development
•Determine
user
requirements
system
performance
•Develop
details of system
team
•Recommend solution
•Train
users
•Assess
system
security
Implementation
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Design
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Information system development
Who participates in the system development cycle?
 Project team includes both nontechnical user and It
professionals.
 System analyst is designing and developing an
information system.
 Project leader one member of the team whose
manages and controls the budget and schedule of the
project.
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Information system development
Project management
is the process of planning, scheduling and then controlling
the activities during the system development cycle.
Documentation
is the collection and summarization of data and information.
 It includes reports, diagrams, programs or any other
information generated during the system development
cycle.
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Programming Languages
Computer program is a series of instruction that
directs a computer to perform tasks.
Computer programmer, some times called a
developer, writes and modifies computer
programs.
Programming language is a set of words,
symbols and codes that enables a programmer
to communicate instructions to a computer.
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Programming Languages
Two type of languages are low-level and highlevel.
Low-level language is a programming language
that is machine dependent which runs on only
one particular type of computer.
High-level languages often are machine
independent which runs on many different types
of computers and operating systems.
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Programming Languages
low-level languages
Machine language
Assembly language
 Known as the first generation of programming language.
 It is the only language the computer directly recognizes.
 Instructions use a series of binary digits or a combination of
numbers and letters that represents binary digits.
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Programming Languages
Assembly language
 Known as the second generation of programming language.
 Programmer write instructions using symbolic instruction codes.
 It can be difficult to learn.
 The computer cannot execute the assembly source program.
 Source program : is the program that contains the language
codes.
To convert the assembly code into machine language,
programmers use a program called an assembler
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Programming Languages
Procedural Languages
The disadvantages of low-level languages led to
development of procedural languages.
Often called a third-generation languages (3GL).
Programmer uses a series of English-like word
to write instructions and arithmetic symbols .
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Programming Languages
Procedural Languages
Programmers typically use either a compiler or an
interpreter to perform the translation ( from source code
to machine code).
 Compiler is a separate program that converts the entire
source program into machine language before executing
it.
 Interpreter reads a code statement converts it to one or
more machine language instructions and then executes
those instructions.
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Programming Languages
Source
Program
Compiler
Object
Program
Program
Listing
Data
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Results
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Programming Languages
Source
Program
Data
Interpreter
Results
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Programming Languages
Procedural Languages
 One advantage of an interpreter is that when it finds
errors, it displays feedback immediately.
 The disadvantage is that interpreted programs do not run
as fast as compiled programs.
 Example of procedural languages is COBOL and C.
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Programming Languages
Object-Oriented Programming Languages
 Programmers use an OOP language or OOP
development tool to implement objects in a program.
 Program development tool is a program that provides a
user friendly environment for building programs.
 A major benefit of OOP is the ability to reuse and modify
existing objects.
 Its work well in a RAD environment.
 Example of OOP languages are Java , C++ and C#.
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The program development cycle
Analyze
Requirements
Design
Solution
Document
Solution
Validate
Design
Test
Solution
Implement
Design
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