Modern Systems Analysis and Design Ch1€¦ · Systems Development Life Cycle (SDLC) (Cont.)...

Chapter 1- (Part 1)

The Systems Development

Environment

Modern Systems Analysis

and Design Sixth Edition

Jeffrey A. Hoffer

Joey F. George

Joseph S. Valacich

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 2 Chapter 1

Learning Objectives

Introduction

Define the usage of information systems analysis and design.

Describe the information Systems Development Life Cycle (SDLC).

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Data, Information, and Knowledge

Data: raw facts

Information: collection of facts organized in

such a way that they have value beyond(وراء)

the facts themselves.

Knowledge: awareness(الوعي والمعرفة) and

understanding of a set of information and ways

that information can be made useful to support a

specific task or reach a decision

Introduction

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Figure : The Process of Transforming Data into Information

Data, Information, and Knowledge

(continued)

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System Concepts

System

A set of elements or components that interact

to accomplish goals

Components of a system

Input

Processing

Output

Feedback

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Input, Processing, Output, Feedback

Input: activity of gathering and capturing raw

data

Processing: converting or transforming data

into useful outputs

Output: production of useful information, usually

in the form of documents and reports

Feedback: output that is used to make changes

to input or processing activities

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System Concepts (continued)

Components of a System

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What Is An Information System?

The Components of an Information System

An Information System

A set of interrelated components that collect,

manipulate, and disseminate(نشر), store and

process data into information, and provide

feedback to meet an objective

System users, business managers, and

information systems professionals must work

together to build a successful information system.

Example: A payroll system, for example, collects information on employees and their work, processes and stores that information, and then produces paychecks and payroll reports for the organization.

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 10 3/14/2016Chapter 1

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Computer-based information system (CBIS)

A single set of hardware, software, databases,

telecommunications, people, and procedures

that are configured to collect, manipulate, store,

and process data into information.

Computer-based Information System (CBIS):

An information system that uses computer

technology to perform some or all of its

intended(مقصودة) tasks.

Examples: Airline reservation systems.

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Computer-Based Information Systems (cont.)

The Components of a Computer-Based Information System

Systems analysis and design

Systems analysis and design – the

process of planning, analysis, designing,

building, and maintaining information

system.



Information Systems Analysis and Design

Complex organizational process

Used to develop and maintain computer-based information systems

Used by a team of business and systems professionals

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Introduction (Cont.)

15 Chapter 1

FIGURE 1-1 An organizational approach to systems analysis and

design is driven by methodologies(Phases), techniques(Method), and tools (ex. UML)


A Modern Approach to Systems Analysis and

Design

1950s: focus on efficient(كفاءة) automation of existing processes

1960s: advent of 3GL, faster and more reliable(وثوقية واعتمادية) computers

1970s: system development becomes more like an engineering discipline(انضباط)


A Modern Approach to Systems Analysis

and Design (Cont.)

1980s: major breakthrough with 4GL, CASE tools, object oriented methods

1990s: focus on system integration, GUI (Graphical User Interface ( applications, client/server platforms, Internet

The new century: Web application development, wireless PDAs (personal data assistant) , component-based applications


A Modern Approach to Systems Analysis

and Design (Cont.)

Application Software

Computer software designed to support

organizational functions or processes

Systems Analyst

Organizational role most responsible for

analysis and design of information systems

Role of the Systems Analyst

Study problems and needs of an organization

Determine best approach to improving organization

through use of:

People

Methods

Information technology

Help system users and managers define their

requirements for new or enhanced systems

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Skills of a Successful Systems Analyst Analytical

Understanding of organizations

Problem-solving skills

System thinking

Ability to see organizations and information systems as systems

Technical

Understanding of potential and limitations of technology

Managerial

Ability to manage projects, resources, risk and change

Interpersonal (بين األشخاص)

Effective written and oral communication skills

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Developing Information Systems

System Development Methodology is a standard

process followed in an organization to conduct all

the steps necessary to analyze, design, implement,

and maintain information systems.

System Development Life Cycle

Systems Development Life Cycle (SDLC)

Traditional methodology used to develop,

maintain, and replace information systems.

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System Development Life Cycle

phases

Following are the different phases of System Development Life Cycle :

Planning

Analysis

Design

Implementation

Maintenance

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SDLC ’s Phases

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(Cont.)

1\ Planning – an organization’s total

information system needs are identified,

analyzed, prioritized, and arranged.

Phase of planning:

User request

Feasibility study

Project Plan

Project Proposal


Systems Development Life Cycle(SDLC) (Cont.)

Planning:

The problems in the old system like:

The difficulty of using the system

System slowdowns

High cost in the operation of the system

Frequent failure in the system

Appearance a new technology useful for the goals of

the system

Shortage in output

Lack of security in


Planning In this phase, someone identifies the need for a

new or enhanced system.

The project leader and initial team of system analyst produce a specific plan for a proposed system project.

A detailed plan is also developed for conducting the remaining phases of the SDLC for the proposed system.

Also, feasibility study conducted in this phase.

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System Development Feasibility Study

Feasibility study

A study that determines whether a requested

system makes economic and operational

sense for an organization.

In the process of feasibility study, the cost and benefits are estimated with greater accuracy(بدقة).

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(Cont.)

Analysis – system requirements are studied and structured

WHAT SHOULD THE SYSTEM CONTAIN ?

REQUIREMENTS ANALYSIS

DATA COLLECTION

INTERVIEWS, QUESTIONNAIRES, JAD,..

PROBLEM

USERS DON’T ALWAYS KNOW WHAT THEY WANT


Analysis

The first is requirements determination which the system analyst work with users to determine what the users want from the proposed system.

Next the system analyst study the requirements and structure them according to their interrelationships.

Then system analyst generate alternative initial design to match the requirements.

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Systems Development Life Cycle(SDLC) (Cont.)

System Design The description of the recommended

alternative solutions is converted into logical and then physical system specification.

You must design all aspects of the system from input and output screens to reports, database, and computer processes.

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Systems Development Life Cycle (SDLC) (Cont.)

Logical design – Functional, detailed specifications of all system elements (data, processes, input, outputs)




Physical design – the logical specifications of

the system from logical design are transformed

into the technology-specific details from which

all programming and system construction can

be accomplished(إنجاز)

Technical, detailed specifications of all system

elements (programs, files, network, system

software).


Implementation

Detailed model or detailed written specifications are turned to programmer as the first part of implementation phase.

Implementation includes coding, testing, and installation.

Coding: programmers write the programs that make up the system.

Testing: programmers and analysts test individual programs and the entire system in order to find and correct the errors.

Installation: the new system becomes a part of the daily activities of the organization.

.

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Maintenance

An information system is systematically repaired and improved.

When a system is operate in organization, users sometimes find problems with how it works and often think of better ways to perform its functions.

Programmers make the changes that users ask for and modify the system to reflect changing business condition.

So the final phase of SDLC improve information system.

35

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

FIGURE 1-8

The heart of systems development

Chapter 1

The Heart of the Systems Development Process

Current practice combines analysis, design, and implementation

into a single iterative and parallel process of activities.

FIGURE 1-7

The analysis–design–code–test loop


Summary

In this first part of chapter you learned

how to: Define information systems analysis and design.

Describe the information Systems Development Life Cycle (SDLC).

Modern Systems Analysis and Design Ch1€¦ · Systems Development Life Cycle (SDLC) (Cont.)...

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