Systems Analysis & Design Seventh Edition C HAP 1: I NTRO TO SAD 1

Systems Analysis & Design

Seventh Edition

CHAP1: INTRO TO SAD1

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CHAPTER OBJECTIVES Discuss the impact of information technology

on business strategy and success Define and describe an information system

components Use profiles and models to understand

business functions and operations Explain how the Internet has affected

business strategies and relationships Identify various types of information systems

and explain who uses them

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CHAPTER OBJECTIVES

Explain systems development tools, including modeling, prototyping, and CASE tools

Distinguish between structured analysis and object-oriented methodology

Describe the systems development life cycle Discuss the role of the information

technology department and the systems analysts who work there

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INTRODUCTION

The use of informationas a weapon in the battle

increase productivity, deliver quality products and services,

maintain customer loyaltymake correct/strong decisions

IT can mean the difference between success and failure

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THE IMPACT OF INFORMATION TECHNOLOGY

Definition: Information Technology (IT) Combination of hardware and software

products and services that companies use to manage, access, communicate, and share information

A vital asset that must be used effectively, updated constantly safeguarded carefully

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The Future of IT Accounted for almost 30 percent of economic

growth in 2003 Online population worldwide increased 106

percent between 2000-2004 305.5% usage growth 2000-2008

Note: http://www.internetworldstats.com/

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http://www.internetworldstats.com/

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The Role of Systems Analysis and Design Definition: Systems Analysis and Design

Step-by-step process for developing high-quality information systems

Systems Analyst (SA) Plan, develop, and maintain information systems

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THE IMPACT OF INFORMATION TECHNOLOGY Who Develops Information Systems?

In-house applications Software packages Internet-based application services Outsourcing Custom solutions Enterprise-wide software strategies How versus What – how the system will be

implemented before determining what the system is supposed to do = high risk

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INFORMATION SYSTEM COMPONENTS A system is a set of

related components that produces specific results

A mission-critical system is one that is vital to a company’s operations Business cannot be

done without it

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INFORMATION SYSTEM COMPONENTS

1) Hardware – consist of everything in the physical layer of the information system Servers, workstations, networks,

telecommunications equipment, etc 2) Software – program that control the h/ware

and produce the desired result System software – manage h/ware component (e.g.

Win XP) Network operating system – (e.g. Win 2003 Server,

Unix, etc)

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Application software – consist of program that support day-to-day business functions

Enterprise applications – order process system, payroll system, financial system

Horizontal system – inventory or payroll application (e.g. standard payroll system that able to use by all companies)

Vertical system – design to meet unique req. of a business (e.g. special IS that serves to meet unique business req.)

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3) Data Is the raw material that an information system

transforms into useful information Tables Linking

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4) Processes Define the tasks and business functions that

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

5) People (Stakeholder) Users, or end users, are the people who interact

with an information system, both inside and outside the company

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UNDERSTANDING THE BUSINESS

Business Profile – describe company overall functionOrganization, processes, services,

products, customers, suppliers, competitors, constraints, future direction

SA investigates company’s products, services, Internet opportunities

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Business Models – purpose: make it easier for manager and system analyst to understand day-to-day business operationBusiness models – a framework in creating

value (e.g. selling computer – Dell)Business process – specific (tasks|

processes) that involved in creating value BPR (business process reengineering) –

trying to simplify current processes or reduce cost

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New Kinds of CompaniesProduct-oriented – routers,

microchipsService-oriented – resellers and

providers of informationBrick-and-mortar – conduct

business from physical locations (have premises)

Dot-com (.com) or Internet-dependent Amazon.com, Google, eBay, Yahoo!

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IMPACT OF THE INTERNET

E-Commerce (I-Commerce) B2C (Business-to-Consumer) B2B (Business-to-Business)

Electronic Data Interchange (EDI), XML, HTML

Web-Based Development Solutions IBM WebSphere Modeler, Microsoft .NET Web services

Developed by 3rd party developer but included as part of the IS

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HOW BUSINESS USES INFORMATIONSYSTEMS

IT managers divided systems into categories based on the user group the system served Office systems Operational systems Decision support systems Executive information systems

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HOW BUSINESS USES INFORMATION SYSTEMS (TYPE OF IS) Today, it makes more sense to identify a

system by its functions, rather than by users Enterprise computing systems – support

company-wide operation and data mgt req.Transaction processing systems – data

generated by day-to-day operationsBusiness support systems – provide job-

related information to users at all levels of a company

Knowledge management systems – expert system, combine knowledge base and inference rule

User productivity systems – email, voice mail, fax, etc

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HOW BUSINESS USES INFORMATION SYSTEMS (TYPE OF IS)

Enterprise computing systems Support company-wide operations and data

management requirements Enterprise resource planning (ERP)

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Transaction processing systems (TPS) Efficient because they process a set of transaction-

related commands as a group rather than individually

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Business support systems Provide job-related information to users at all

levels of a company Management information systems (MIS) Radio frequency identification (RFID) What-if analysis

e.g: What will happen if fuel price continues decreasing?

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Knowledge management systems Called expert systems Simulate human reasoning by combining a

knowledge base and inference rules Many use fuzzy logic and neural network

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User productivity systems Technology that improves productivity Groupware

Information systems integration Most large companies require systems that

combine transaction processing, business support, knowledge management, and user productivity features Common Object Request Broker Architecture (CORBA)

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INFORMATION SYSTEM USERS AND THEIR NEEDS

A SA must understand the company’s organizational model in order to recognize who is responsible for specific processes and decisions and to be aware of what information is required by whom

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INFORMATION SYSTEM USERS AND THEIR NEEDS

Top managers – develop long range plans called strategic plans, define the company overall mission and goals (SISP)

Middle Managers and Knowledge Workers - just below the top level, provide direction,

resources and performance feedback to teams and supervisors

Supervisors and Team Leaders – carry out day-to-day functions and oversee operational employees

Operational Employees – users who rely on TPS to enter and receive data

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SYSTEMS DEVELOPMENT TOOLS AND TECHNIQUES

SA must know how to use a variety of techniques such as modeling, prototyping, and computer-aided systems engineering tools to plan, design, and implement information systems

SA work with these tools in a team environment

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ModelingUsed to describe and simplify an IS:Business or requirements model –

information that a system must provideData model – data structures and design Object model – consist of data and processNetwork model – design and protocols of

telecomm. linksProcess model – logic that programmers use

to write code modules

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Prototyping Definition: an early working version of an IS Adv: Speeds up the development process Disadv: Important decisions might be made too

early, before business or IT issues are thoroughly understood

Can be an extremely valuable tool

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Computer-Aided Systems Engineering (CASE) Tools Framework for systems development and

support a wide variety of design methodologies CASE tools – make easier to built an information

system, boost IT productivity and improve the quality of the finished product.

Upper CASE – (conceptual|logical) design Lower CASE – physical design

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SYSTEMS DEVELOPMENT METHODS

Structured analysis and object-oriented analysis are both popular methodologies for developing computer-based information systems

A SA should understand the alternative methodologies and their individual strengths and weaknesses

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Structured Analysis Uses a set of process models to describe a

system graphically Systems development life cycle (SDLC)

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Object-oriented (O-O) analysis O-O analysis combines data & processes into

objects Object is a member of a class Class is a collection of similar objects Objects possess properties Methods change an object’s properties Messages request specific behavior or

information from another object

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Joint Application Development and Rapid Application Development JAD – Team based fact finding RAD – compressed version of the entire process

Other development methodologies Microsoft Solutions Framework (MSF) Spiral Model Extreme Programming RUP

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THE SYSTEMS DEVELOPMENT LIFE CYCLE

SDLC used to plan and manage the systems development process

It includes the following steps:Systems planning phaseSystems analysis phaseSystems design phaseSystems implementation phaseSystems operation, support, and security

phaseDeliverable or end product

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Traditionally pictured as a waterfall model, but is also presented as an interactive model depicting real world practice and the constant dialog among users, managers, and systems developers

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Systems Planning To identify the nature and scope of the business

opportunity or problem Systems request – begins the process &

describes problems or desired changes Systems planning includes preliminary

investigation whose key part is a feasibility study End product: Preliminary Investigation

Document, Software Development Plan (SDP)

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Systems Analysis To build a logical model of the new system First step is requirements modeling, where you

investigate business processes and document what the new system must do

End product: system requirements document

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Systems Design Purpose is to create a blueprint that will satisfy

all documented requirements Identify all outputs, inputs, and processes Avoid misunderstanding through manager and

user involvement End product: systems design specification

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Systems Implementation New system is constructed Write, test, & document programs File conversion occurs Users, managers, IT staff trained to operate and

support the system Systems evaluation performed

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Systems operation, support, and security New system supports operations Maintenance changes correct errors or meet

requirements Enhancements increase system capability Well-designed system will be secure, reliable,

maintainable, and scalable SDLC ends with system replacement

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SYSTEMS DEVELOPMENT GUIDELINES

Planning Involve users throughout the development

process Listening is very important Create a time table with major milestones Identify interim checkpoints Remain flexible Develop accurate cost and benefit information

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INFORMATION TECHNOLOGY DEPARTMENT

The information technology (IT) department develops and maintains a company’s information systems

The IT group provides technical support

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INFORMATION TECHNOLOGY DEPARTMENT

Application Development Team may include users, managers and IT staff

members Systems Support and Security

Provides hardware and software support User Support

Provides users with technical information, training, and productivity support

Help desk

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INFORMATION TECHNOLOGY DEPARTMENT Database Administration

Database design, management, security, backup, and user access

Network Administration Includes hardware and software maintenance,

support, and security Web Support

Design and construction of Web pages and presence

Important for e-commerce Webmaster

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THE SYSTEMS ANALYST POSITION

A systems analyst investigates, analyzes, designs, develops, installs, evaluates, and maintains a company’s information systems

On large projects, the analyst works as a member of an IT department team

Smaller companies often use consultants to perform the work

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Responsibilities Translate business requirements into practical IT

projects to meet needs Required Skills and Background

Solid communication skills and analytical ability

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Certification Professional credential

Career Opportunities Job titles Company organization Company size Corporate culture Salary, location, and future growth

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CHAPTER SUMMARY

IT is a combination of hardware and software that support business

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

Companies are product-oriented, service-oriented, or a combination of the two

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CHAPTER SUMMARY

Organization structure usually includes levels. Each level has different responsibilities and information needs

Systems analysts use modeling, prototyping, and CASE tools. Modeling produces a graphical representation of the process, prototyping involves creation of an early working model, and CASE tools assist in various systems development tasks

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CHAPTER SUMMARY The Systems Development Life Cycle (SDLC)

consists of five phases: systems planning, systems analysis, systems design, systems implementation, and systems operation, support, and security

Systems analysts need a combination of technical and business knowledge, analytical ability, and communication skills

Chapter 1 Complete

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Documents

Systems Analysis & Design Seventh Edition C HAP 1: I NTRO TO SAD 1