introduction to system analysis and design (definition of system & information system...

Introduction to System Introduction to System Analysis and DesignAnalysis and Design

(Definition of System & information (Definition of System & information

system components)system components) - Dr. Mahmoud Abu-Arra- Dr. Mahmoud Abu-Arra

- Mr. Ahmad Al-Ghoul- Mr. Ahmad Al-Ghoul

System Analysis and System Analysis and DesignDesign

AvicennaAvicenna System Analysis and Design IntSystem Analysis and Design Introduction to SADroduction to SAD

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learning Objectiveslearning Objectives

Describe the characteristics of Describe the characteristics of systemsystem

Define an information system and Define an information system and describe its componentsdescribe its components


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introductionintroduction Before talking about the characteristics of systems, and Before talking about the characteristics of systems, and

information system components let us have a historical view for information system components let us have a historical view for the system analysis and design.the system analysis and design.

The analysis and design of a computer based information systems The analysis and design of a computer based information systems began in the 1950s.began in the 1950s.

Since then, the development environment has changed dramatically, Since then, the development environment has changed dramatically, driven by organizational needs as well as by rapid changes in the driven by organizational needs as well as by rapid changes in the technological capabilities of computerstechnological capabilities of computers

In the 1950s, development focused on the processes the software In the 1950s, development focused on the processes the software performedperformed

Computer power was critical resource, efficiency of processing become Computer power was critical resource, efficiency of processing become the major goalthe major goal

Computer were large, expensive, and not very reliableComputer were large, expensive, and not very reliable All applications had to be developed in machine language or assembly All applications had to be developed in machine language or assembly

languagelanguage Software had to be developed from scratch, because there was no Software had to be developed from scratch, because there was no

software industry software industry


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introductionintroduction

second step 1960ssecond step 1960s The second step begins with the first procedural, The second step begins with the first procedural,

or third generation, computer programming or third generation, computer programming languages in the beginning of 1960slanguages in the beginning of 1960s

Computers were still expensive and large but it Computers were still expensive and large but it gets more smaller and faster, less expensive gets more smaller and faster, less expensive than 1950sthan 1950s

With the third generation programming With the third generation programming languages, software industry begins, but most languages, software industry begins, but most organizations still developed their applications organizations still developed their applications from scratch using their in-house development from scratch using their in-house development staffstaff


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Third step 1970sThird step 1970s Organizations began to realize how expensive Organizations began to realize how expensive

it was to develop customized information it was to develop customized information systems for every applicationsystems for every application

early database management systems, using early database management systems, using hierarchal and network models helped storage hierarchal and network models helped storage and retrieval of dataand retrieval of data

The development of database management The development of database management systems helped shift the focus of systems systems helped shift the focus of systems development from processes first to data firstdevelopment from processes first to data first


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Fourth step 1980sFourth step 1980s Microcomputers become key organizational toolsMicrocomputers become key organizational tools The software industry expanded greatly as more and more people The software industry expanded greatly as more and more people

began to write off-the-shelf software for microcomputersbegan to write off-the-shelf software for microcomputers Developers began to write more and more applications in fourth Developers began to write more and more applications in fourth

generation languages, which unlike procedural languages, instructed a generation languages, which unlike procedural languages, instructed a computer on what to do instead of how to do itcomputer on what to do instead of how to do it

Computer-aided software engineering (CASE) tools were developed to Computer-aided software engineering (CASE) tools were developed to make systems developers work easiermake systems developers work easier

A computer get smaller, faster, and cheaperA computer get smaller, faster, and cheaper The operating systems for computers moved away from line prompt The operating systems for computers moved away from line prompt

interface to windows and icon based interfacesinterface to windows and icon based interfaces Organizations moved to applications with more graphicsOrganizations moved to applications with more graphics Organizations developed less software in-house and bought relatively Organizations developed less software in-house and bought relatively

more from software vendorsmore from software vendors System developer’s job went through a transition from builder to System developer’s job went through a transition from builder to

integratorintegrator


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Fifth step 1990sFifth step 1990s Developers used visual programming environments, Developers used visual programming environments,

such as power builder or visual basic, to design the such as power builder or visual basic, to design the user interfaces for systems that run on client/server user interfaces for systems that run on client/server platformsplatforms

Databases become relational or object oriented, and Databases become relational or object oriented, and which may have been developed using software from which may have been developed using software from firms such as Oracle, Microsoft. resided on the serverfirms such as Oracle, Microsoft. resided on the server

Application logic resided on the same server with the Application logic resided on the same server with the database, alternatively, an organization may have database, alternatively, an organization may have decided to purchase its entire enterprise wide decided to purchase its entire enterprise wide systemsystem

More and more systems development efforts More and more systems development efforts focused on the Internet, especially the webfocused on the Internet, especially the web


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Sixth step the new centurySixth step the new century The focus on developing systems for the Internet and for The focus on developing systems for the Internet and for

firm’s intranets and extranetsfirm’s intranets and extranets Many CASE tools, such as those developed by Oracle, Many CASE tools, such as those developed by Oracle,

now directly support Web application developmentnow directly support Web application development System implementation involves a three-tier design, System implementation involves a three-tier design,

with the database on one server, the application on a with the database on one server, the application on a second server, and client logic located on user machinessecond server, and client logic located on user machines

Moving to wireless system components, wireless Moving to wireless system components, wireless devices, such as cell phonesdevices, such as cell phones

In some cases organizations not only do not develop the In some cases organizations not only do not develop the application in-house; they don’t even run the application application in-house; they don’t even run the application in-house, choosing instead to use the application on a in-house, choosing instead to use the application on a per-use basis by accessing in through an application per-use basis by accessing in through an application service provider (ASP) service provider (ASP)


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Characteristics of SystemsCharacteristics of Systems

A system A system interrelated components working together for a common purpose

Information system (IS)Information system (IS) Arrangement of people, data, processes, Arrangement of people, data, processes,

information presentation and information information presentation and information technology that interact to support and technology that interact to support and improve day-to-day operations in a improve day-to-day operations in a business as well as support the problem-business as well as support the problem-solving and decision-making needs of solving and decision-making needs of management and users management and users


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Characteristics of SystemsCharacteristics of Systems Systems are made up of Systems are made up of interrelated subsystemsinterrelated subsystems (e.g. a nuclear (e.g. a nuclear

reactor is composed of boilers, reactor components etc.)reactor is composed of boilers, reactor components etc.)

Functional decompositionFunctional decomposition – dividing a system into components – dividing a system into components

based on subsystems (which are in turn further divided into based on subsystems (which are in turn further divided into

subsystems)subsystems)

Functional & Non-Functional components of a systemFunctional & Non-Functional components of a system

System boundarySystem boundary – the separation between a system and its – the separation between a system and its

environment (where inputs and outputs cross)environment (where inputs and outputs cross)

Automation boundaryAutomation boundary – separation between the automated part – separation between the automated part

of system and the manual partof system and the manual part


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Manual Part of the System

Automated Part of the System

Automationboundary

Systemboundary

Environment Surrounding the System

The system boundary and the automation boundary


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output

boundary

interrelationship

subsystem

input

input

General Depiction of a System


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Information System Information System ComponentsComponents

Information systems have five key Information systems have five key components: hardware, software, components: hardware, software, data, processes, and peopledata, processes, and people

people

processes

data

software

hardware


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HardwareHardware Is the physical layer of the information Is the physical layer of the information

systemsystem

Hardware includes: work stations, servers, Hardware includes: work stations, servers, networks, telecommunication equipments, networks, telecommunication equipments, cables, input and output devices and many cables, input and output devices and many others.others.

Hardware has become more powerful that give Hardware has become more powerful that give information systems more opportunities, and information systems more opportunities, and it also cut costs by becoming less expensive.it also cut costs by becoming less expensive.


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Information System Information System ComponentsComponents SoftwareSoftware

Software refers to the programs which control the Software refers to the programs which control the hardware and produce the desired information and hardware and produce the desired information and resultsresults

Software consists of system software and application Software consists of system software and application softwaresoftware System softwareSystem software manages the hardware manages the hardware

components, which can include a single workstation components, which can include a single workstation or global network. Examples of system software or global network. Examples of system software include include

operating systemsoperating systems security software,security software, that protects the computer that protects the computer

from intrusion from intrusion utility programs,utility programs, that handle specific tasks such as that handle specific tasks such as

data backup and disk management. data backup and disk management. Network operating system (NOS)Network operating system (NOS), which controls , which controls

data, provide data security, manage network data, provide data security, manage network accounts.accounts.


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SoftwareSoftware Application softwareApplication software, , the programs that the programs that

support day-to day business functions and support day-to day business functions and provide process and manage the information user provide process and manage the information user need. Application software can serve one or any need. Application software can serve one or any number of users. Examples of company-wide number of users. Examples of company-wide applications, called applications, called Enterprise applicationsEnterprise applications, , include order processing system, payroll systems, include order processing system, payroll systems, and company communication networkand company communication network Application software includes horizontal and Application software includes horizontal and

vertical systemsvertical systems A horizontal system is a system, such as an inventory A horizontal system is a system, such as an inventory

or payroll application, that can be adapted for use in or payroll application, that can be adapted for use in many different types of companiesmany different types of companies

A vertical systems is designed to meet the unique A vertical systems is designed to meet the unique requirements of a specific business, such as a requirements of a specific business, such as a medical practice, or a video chain.medical practice, or a video chain.


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Information System Information System ComponentsComponents Data Data

Is the raw material that an information system Is the raw material that an information system transforms into useful informationtransforms into useful information

Data can be stored in various locations, called Data can be stored in various locations, called tablestables

The system can extract specific information by The system can extract specific information by linking the tableslinking the tables

Processes Processes Define the tasks and business functions that users, Define the tasks and business functions that users,

managers, and IT staff members perform to managers, and IT staff members perform to achieve specific resultsachieve specific results

Processes are the building blocks of an information Processes are the building blocks of an information systemsystem

Processes represent actual day-to-day business Processes represent actual day-to-day business operationsoperations


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PeoplePeople those who operate the system; those who those who operate the system; those who

provide its inputs and consume its outputs, and provide its inputs and consume its outputs, and those who provide manual processing activities those who provide manual processing activities in a system, Users are the people who interact in a system, Users are the people who interact with an information system, both inside and with an information system, both inside and outside the companyoutside the company

We can divide users to two types internal and We can divide users to two types internal and externalexternal

Internal users include administrators, managers, Internal users include administrators, managers, technicians, sales staff, and corporate officerstechnicians, sales staff, and corporate officers

External users include customers who track their orders External users include customers who track their orders on the company’s Web site and suppliers who use a on the company’s Web site and suppliers who use a customer’s system to plan their manufacturing customer’s system to plan their manufacturing schedules.schedules.


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Sequence SummarySequence Summary

In this sequence, you learned about how systems In this sequence, you learned about how systems analysis and design in organizations has changed analysis and design in organizations has changed over the past 40 yearsover the past 40 years

A system interrelated components working together A system interrelated components working together for a common purposefor a common purpose

Information system (IS) is Information system (IS) is arrangement of people, arrangement of people, data, processes, information presentation and data, processes, information presentation and information technology that interact to support and information technology that interact to support and improve day-to-day operations in a businessimprove day-to-day operations in a business

Systems are made up of interrelated subsystems can Systems are made up of interrelated subsystems can be divided into sub systems depending on its be divided into sub systems depending on its functionsfunctions

The essential components of an information system The essential components of an information system are are hardware, software, data, processes, and peoplehardware, software, data, processes, and people


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Sequence SummarySequence Summary

In this Sequence we haveIn this Sequence we have Described how systems analysis and Described how systems analysis and

design in organizations has changed design in organizations has changed over the past 40 yearsover the past 40 years

Defined the terms system and Defined the terms system and information systeminformation system

Described the characteristics of systemDescribed the characteristics of system Described information system Described information system

componentscomponents


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ReferenceReference

[1] System Analysis and Design, Sixth Edition[1] System Analysis and Design, Sixth Edition Authors: Gary B. Shelly, Thomas J. Cashman and Harry J. Rosenblatt , Authors: Gary B. Shelly, Thomas J. Cashman and Harry J. Rosenblatt , Publisher: SHELLY CASHMAN SEWIES.Publisher: SHELLY CASHMAN SEWIES.

[2] Modern Systems Analysis and Design Third Edition[2] Modern Systems Analysis and Design Third Edition Authors: Jeffrey A. Hoffer , Joey F. George, Joseph S. ValacichAuthors: Jeffrey A. Hoffer , Joey F. George, Joseph S. Valacich Publisher: prentice hall Publisher: prentice hall

introduction to system analysis and design (definition of system & information system...

Documents

design introduction

designsystem analysis

integratorsystem analysis

componentssystem analysis

characteristics of systems

systems developers

customized information

focus of systems development