Chap 1 Intro to Systems Analysis and Design

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Chapter 1

Systems Analysis & Design7th Edition

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Chapter Objectives

Discuss the impact of information technology on business strategy and success

Define an information system and describe its components

Explain how profiles and models can represent 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 modeling, prototyping, and CASE tools Distinguish between structured analysis and object-

oriented analysis Compare the systems development life cycle

waterfall model to adaptive models Discuss the role of the information technology

department and the systems analysts who work there

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Introduction

Companies use information as a weapon in the battle to increase productivity, deliver quality products and services, maintain customer loyalty, and make sound decisions

Information technology can mean the difference between success and failure

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The Impact of Information Technology

Information Technology – 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, and safeguarded carefully

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The Impact of Information Technology

The Future of IT– Accounts for almost 30 percent of America’s

economic growth, and the wage gaps between IT workers and all other workers will continue to widen

– Global online population skyrocketed between 2000 and 2005

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The Impact of Information Technology

The Role of Systems Analysis and Design– Systems Analysis and Design

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

– Systems Analyst• 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

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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

Data consists of basic facts that are the system’s raw material

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Information System Components

Hardware – Moore’s Law

Software– System software– Application software – Enterprise applications– Horizontal system

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Information System Components

Software– Vertical system– Legacy systems

Data – Tables– Linking

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Information System Components

Processes – Define the tasks and business functions that users,

managers, and IT staff members perform to achieve specific results

People– 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 Process ModelingBusiness ProfileBusiness Models

– Business model– Business process– Business process reengineering (BPR)

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Understanding The Business

New Kinds of Companies– Production-oriented – Service-oriented– Internet-dependent– Dot-com (.com)– Brick-and-mortar

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Impact of the Internet

E-Commerce or I-CommerceB2C (Business-to-Consumer)B2B (Business-to-Business)

– EDI– Extensible markup language (XML)– Supplier relationship management (SRM)

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Impact of the Internet

Web-Based System Development– WebSphere– .NET– Web services

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How Business Uses InformationSystems

In past, 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

Today, it makes more sense to identify a system by its functions, rather than by users – Enterprise computing systems– Transaction processing systems– Business support systems– Knowledge management systems– User productivity systems

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How Business Uses Information Systems

Enterprise computing systems– Support company-wide

operations and data management requirements

Transaction processing systems– Efficient because they process a

set of transaction-related commands as a group rather than individually

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How Business Uses Information Systems

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

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How Business Uses Information Systems

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

base and inference rules– Many use fuzzy logic

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How Business Uses Information Systems

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

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Information System Users and Their Needs

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Information System Users and Their Needs

Top managersMiddle Managers and Knowledge Workers Supervisors and Team Leaders Operational Employees

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Systems Development Tools and Techniques

Modeling– Business model– Requirements model– Data model– Object model– Network model– Process model

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Systems Development Tools and Techniques

Prototyping– Prototype– Speeds up the development process significantly– 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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Systems Development Tools and Techniques

Computer-Aided Systems Engineering (CASE) Tools– Also called computer-aided software engineering

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Systems Development Methods

Structured Analysis– Systems development life cycle (SDLC)– Predictive approach– Uses a set of process models to describe a system

graphically– Process-centered technique

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Systems Development Methods

Object-oriented Analysis– O-O analysis combines data & processes into objects– Object is a member of a class– Objects possess properties– Methods change an object’s properties– A message requests specific behavior or information

from another object

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Planning and Modeling a Systems Development Project

In addition to selecting a development method, system developers also must create a plan or model for the many tasks that will be required

Typically, the development team will use project management tools to help achieve the end result

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Planning and Modeling a Systems Development ProjectComparison of Predictive and Adaptive

Models– The SDLC usually is referred to as the waterfall model

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Planning and Modeling a Systems Development ProjectThe SDLC Waterfall Model

– Disadvantage in the built-in structure of the SDLC, because the waterfall model does not emphasize interactivity among the phases

– This criticism can be valid if the SDLC phases are followed too rigidly

– However, adjacent phases usually interact

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Planning and Modeling a Systems Development Project

The SDLC Waterfall Model– Usually includes five steps

• Systems planning• Systems analysis• Systems design• Systems implementation• Systems operation, support, and security

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Planning and Modeling a Systems Development Project

Systems planning– Systems request– Purpose of this phase is to perform a preliminary

investigation whose key part is a feasibility study

Systems Analysis– First step is requirements modeling– End product is the System requirements document

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Planning and Modeling a Systems Development Project

Systems Design– Identify all outputs, inputs, and processes– End product is system design specification

Systems Implementation– New system is constructed– Users, managers, IT staff trained to operate and

support the system– System evaluation performed

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Planning and Modeling a Systems Development Project

Systems Operation, Support, and Security– A well-designed system must be secure, reliable,

maintainable, and scalable– After several years of operation, systems need

extensive changes – SDLC ends with system replacement

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Planning and Modeling a Systems Development Project

Adaptive Methods and Models– Attempt to develop a system incrementally, by

building a series of prototypes and constantly adjusting them to user requirements

– Extreme Programming (XP)– Analysts should recognize that these approaches

have advantages and disadvantages

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Planning and Modeling a Systems Development Project

Joint Application Development and Rapid Application Development Methods and Models– Joint application development (JAD)– Rapid application development (RAD)

Other Development Methods and Models– Rational Unified Process (RUP®)– Microsoft Solutions Framework (MSF)

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Planning and Modeling a Systems Development Project

The Importance of Project Management– Regardless of the development strategy, people,

tasks, timetables, and expenses must be managed effectively

– Complex projects can involve dozens of people, hundreds of tasks, and many thousands of dollars

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Systems Development Guidelines

Stick to a planInvolve the users throughout the

development processListening is very importantUse project management tools to identify

tasks and milestonesRemain flexibleDevelop 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– Deployment team

User Support– Help desk or information center (IC)

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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– Webmasters

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Information Technology Department

Quality Assurance (QA)– Reviews and tests all applications and systems

changes to verify specifications and software quality standards

– Is a separate unit that reports directly to IT management

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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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The Systems Analyst Position

Responsibilities– Translate business requirements into practical IT

projects to meet needs

Required Skills and Background– Solid communication skills and analytic ability

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The Systems Analyst Position

CertificationCareer 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, software, and telecommunications systems that support business

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

Companies are production oriented, service oriented, or a combination of the two

Organization structure usually includes levels

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Chapter Summary

Systems analyst use modeling, prototyping, and CASE tools

Various development methodologies exist Regardless of the development model, it is important

to use project management tools necessary to manage people, tasks, timetables, and expenses

An IT department develops, maintains and operates a company’s information systems

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Chapter Summary

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

Chapter 1 complete